Ammonia Tank Car Safety

Each installation must have its own properly sized excess flow valve to protect against abreak in the loading or unloading line. A back flow check valve must be installed in the lineused for transfer to prevent from escaping from a break in the line.

F.J. HellerPhillips Petroleum Co.

Bartlesville, OK

I am pleased to appear before the 1980 AIChESymposium on Ammonia Plant Safety and discussammonia tank car safety.

At first glance it may appear strange to bediscussing tank cars in a symposium dedicated toplant safety but when one considers that these bigtanks on wheels come rolling through your gatesinto your plant area then one realizes that heshould know something about tank cars in order tohave a complete plant safety package.

For your information I want to tell you what thetank car industry and the railroad industry aredoing to improve tank car safety and also howammonia plant personnel can help in improvingsafe transportation of your products.

First, let's look at ammonia tank cars. Anhydrousammonia is transported as a compressed gasprimarily in DOT105A300W, DOT112S340W andDOT114S340W tank cars. It may also be trans-ported in 112 and 114 "J" or "T" tank cars whichare dual purpose LPG and anhydrous ammonia tankcars. Class 112A and 114A tank cars are authoriz-ed for anhydrous ammonia until the end of 1980.

The 105 specification is an insulated tank car withapproximately 4 inches of insulation. The 112 and114 specifications were formerly uninsulated tankcars that have had top and bottom shelf couplersand additional safety features added. The letters"S", "3" and "T" have the following significances!"S" means the tank car is uninsulated and has added

head shields; "3" signifies that the tank car hasapproximately a one inch thermal barrier coveredby an outer jacket with & inch jacket heads which •act as a head shield and "T" denotes that the tankhas a spray-on thermal coating and is protectedwith head shields.

A few words of caution - the DOT regulationsprescribe the amount of ammonia that can beloaded into a tank car. The regulations prescribethe maximum permitted filling density expressed inpercent ratio of the weight of ammonia in the tankto the weight of water that the tank will hold.There are different maximums for summer andwinter loading for uninsulated tanks. The "3" and"T" cars have some insulation or spray coating,respectively, but for loading purposes they are stillconsidered to be uninsulated tanks. The addition ofhead shields, new couplers, coatings, insulation andjackets have added measurably to the weight of thecars: therefore, special note needs to be made ofthe light weight (tare weight) of the tank car andthe weight of ammonia loaded so not to exceed themaximum allowable weight on the rails of 263,000pounds. For larger tank cars, anhydrous ammoniaprobably cannot be loaded to the prescribed DOTfilling density without exceeding the maximumpermitted weight on the rails of 263,000 Ibs.Therefore, these larger cars in the 33,000 gallonrange which have high "light weights" must be lightloaded to a lesser percent than prescribed. Theamount of light loading necessary to stay under the263,000 ib. limit will vary depending upon the lightweight of the tank car.

0149-3701/81/4186 $02.00 © 1981 AIChE

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Compressed gas tank cars are easy to identifybecause they usually have a single protective hous-ing located on top in the center of the tank.Normally this is where all the fittings are located,inside the protective housing which is normallylocated at a tank nozzle which doubles as a man-way.

The tank car fittings on pressure tank cars consistof one safety relief valve, one vapor line valve,two eduction (liquid) line valves, a gaging divice, athermometer well, and a sample line connection.These fittings are fastened to the manway coverplate. The liquid (eduction) and vapor lines areequipped with excess flow valves which are locatedat the cover plate and inside the tank. These areintended only to protect the public and retain theproduct in the car, during transit, should the load-ing valves be sheared off the car in an accident.The eduction lines have pipes extending from theexcess flow valves to the bottom of the car. Theliquid and vapor lines also are equipped with plugor ball valves external to the tank and these areused for connecting loading and unloading lines.

The vapor and liquid eduction valves, have outletsthat are normally two or three inches in diameter.You are cautioned that a long loading or unloadingline connected to this valve may introduce enoughfriction to the flow in it that the tank car excessflow valve may no longer function should there bea break in the line. Many loading and unloadingpoints employ two inch lines and use a reducer atthe three inch tank car valve. This installation aswell as the three inch line installation must havetheir own properly sized excess flow valve toprotect against a break in the loading or unloadingline, also a back flow check valve must be installedin the line used for transfer to the storage tank toprevent the storage tanks contents from backing upinto the tank car or from escaping from a break inthe line. Some tanks cars have two inch eductionvalves with three inch excess flow valves. Thesehave been designed and tested to demonstrate thatthe excess flow valve will close should the valve bewiped off in transportation. I cannot emphasizeenough that plant or bulk plant personnel shouldnot rely on the tank cars excess flow valve to shutoff flow should there be a break in the loading orunloading line. It is very important that theloading or unloading lines be subjected to anengineering study and that they must have theirown properly sized excess flow valves or othermeans of protection. The tank, car excess flowvalve is not intended for plant protection becausethere are too many variables in unloading pointconfigurations to provide an excess flow valve thatwill satisfy all contingencies.

Gaging devices come in a variety of forms. Themost common is the slip tube gage but others aremagnetic float gage and the ultrasonic gage. Thevapor valve is used for various functions. It can beused as a pressure equalizing connection betweenthe tank car and storage tank, as a pressurizingconnection, or as a vent. When using the slip tubegage, remember it is subject to tank pressurewhich can cause sudden upward thrust of the rod.For safety, keep your body clear of the rod whenoperating the gage.

There are several operations which should be per-formed at the tank car loading rack to assuresafety in the plant as well as in transportation. Iwill review these operations to refresh yourmemories.

Starting with receipt of the tank car from therailroad one must see that the cars are properlyplaced at the loading rack. The hand brake mustbe set and wheels blocked at the time the car isspotted to prevent the car from moving. Cautionsigns must be placed on the track or tank car towarn persons approaching from ends of the siding.These signs must be left in place until loading orunloading is complete and the car disconnectedfrom the loading lines. Do not leave a tank carconnected overnight or when unattended.

The warning signs must be of metal, at least 12inches by 15 inches in size, and must bear thewords "Stop - Tank Car Connected" or "Stop - Menat Work". The word "Stop" must be in letters atleast four inches high and the other words inletters at least 2 inches high. The letters must bewhite on a blue background.

It is recommended that derails be placed at ends ofsiding approximately one car length from the carbeing loaded or unloaded, unless the car is protect-ed by a closed and locked switch or gate.

After the tank cars are spotted, they should beinspected. Look for railroad defect cards or "badorder" cards. A defect card is placed, by therailroad, in a holder located near the tank sadle.Its purpose is to protect the car owner against lossand damage for which a handling rail line carrier isresponsible. It is our assurance that damage costsare recoverable from the railroad. A bad ordercard can be located on the routing board or may beattached to some malfunctioning part. It flags thefact that something is wrong but assigns no blame.Either card indicates defects to be repaired andthe card must not be removed, or the car loaded,before repairs are made.

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Safety in handling tank cars is basically the resultof knowledge and training. Loading or unloadingoperations must be performed only by reliablepersons properly instructed and made responsiblefor careful compliance with applicable regulations.Personnel should have a working knowledge of theHazardous Materials Regulations of the Depart-ment of Transportation (DOT). These are found inTitle W of the Code of Federal Regulations (49CFR). Personnel should be made aware of civilpenalties for which they are liable. These arefound in 49 CFR, Part 107. There may also belocal, state, or provincial regulations which govern.None of the information contained herein is intend-ed to conflict with such regulations. The regula-tions% of course, govern.

These are some of the things you need to knowregarding how to handle the tank cars that comeinto your plant. There are other aspects of tankcars that will be of interest to you.

There is no doubt the invitation for me to speak toyou stems from my long tenure as member and pastchairman of the AAR Tank Car Committee.

For those of you not familiar with this committeeit is the Association of American Railroads TankCar Committee. It has 13 members; 7 railroadrepresentatives, 5 shipper organization represen-tatives and one tank car builder organization rep-resentative. This committee is dedicated to tankcar safety and is the approval authority for tankcar specifications, of designs of tank cars, forconstruction practices and for the construction andrepair facilities. No welding is to be performed ona tank car tank unless it is done in an AARcertified shop. Certification follows inspectionand approval by the tank car committee. No newdesign of a tank car can be constructed and placedin rail transportation without approval of thiscommittee. Tank car alterations and repairs mustbe also approved by the committee.

Tank cars turn out to be the most controlledtransportation package. The AAR Tank Car Com-mittees long standing commitment to safety hasmade rail transportation of hazardous materialsone of the safest in the United States.

Most of you will remember the stress corrosioncracking problem that occured in anhydrousammonia nurse tanks a few years ago. The AARTank Car Committee prevented this problem fromoccurring to tank cars because of its technicalcompetence and thorough studies of materials,welding and stress relieving. Quenched andtempered steels are not approved for tank carconstruction.

Even though a tank car is a sound transportationpackage capable of giving long satisfactory servicewithin the environment for which it was designed,accidents have occurred and some have been withchaotic results. I would like to talk some about theaccidents; their causes; corrective measures thathave been taken; something that you can do to helpthe safety record of the tank cars and also some-thing you can not do.

Statistics can be boring and the first draft of thispaper was written with very few statistics but theresult was that the paper appeared to be glossingover the facts. Therefore with your kind indul-gence, lets look at some statistics.

One of the first things that was done after prepar-ing an outline of this paper was to go to the officesof the National Transportation Safety Board to getall the information they had on ammonia tank caraccidents. It was surprising that they had verylittle information. The same thing was repeated atthe U. S. Department of Transportation. However,the record contains the information that in thepast 15 years there have been only 45 railroadderailments involving 65 ammonia tank cars whereammonia was released to the atmosphere. Fatala-ties occured in only four instances. Unfortunatelyderailments involving ammonia tank cars in whichthere were no release of product have not beenmade a part of the record. It is important to knowboth favorable and unfavorable experience in orderto evaluate the effectiveness of built in safetyfeatures. Later some attempt will be made tomake some estimates that will relate to this evalu-ation.

Two accidents involving ammonia tank cars thatare frequently discussed are Crete, Nebraska andGlen Ellen, Illinois.

Feb. 18, 1969 at Crete, Nebraska three anhydrousammonia tank cars sitting on a siding were struckwhen a passing train traveling 52 miles per hourderailed beside the standing cars, one of the tankcars ruptured releasing 29,200 gallons of anhydrousammonia in a semi-populated area killing 9 personsand injuring 53. A lesson to be learned was thatpeople that stayed in their houses survived butthose that ran out of their houses onto the streetwere killed.

At the Glen Ellen,. Illinois (a suburb of Chicago)derailment, the head of an anhydrous ammoniatank car was punctured by the coupler of anadjacent car. Several hundred people were evac-uated from their homes but there were no injuries.

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This indicates that ammonia tank cars have had anexcellent safety record but before we becomecomplacent, lets take a look from another angle:In any derailment involving tank cars the potentialexists that there will be some release of product.If the product is flammable or toxic then therelease has a potential of creating more seriousproblems. So how many times have ammonia tankcars been involved in derailments? As I mentioned,this information has not been reliably reported butlets consider the fact that there are 178,000 tankcars of all kinds in the national fleet. Thisrepresents about 10 % of the total number offreight cars in the U. S. There are about 23,000jumbo uninsulated tank cars in the U. S. Fleet.These are the kind that are most actively used totransport LPG and anhydrous ammonia. Theserepresent the number one and number twocompressed gases volumewise that are moved byrail. There are also about 34,000 insulated tankcars of the 105A class that are used less frequentlyfor anhydrous ammonia shipments but more fre-quently when anhydrous ammonia is placed instorage in transit. Therefore about 30% of thetank car fleet are pressure tank cars. This thenequates to the fact that 3% of the total freight carnational fleet are pressure tank cars.

It is therefore not suprising that one finds tankcars on the consist of many freight trains which in1979 averaged 66 freight cars per train. Thesefreight trains rolled to 447,164,000 freight trainmiles in 1979 on class 1 railroads. Figures have notbeen published regarding the number of derail-ments in 1979 but it would be not too far off topredict that there were from 8,000 to 10,000derailments in 1979 or roughly 1 derailment forevery 50,000 train miles.

Strictly statistically and not based upon any actualderailment data this equates to 1 derailment perevery 3.3 million freight car miles.

Again statistically in every 66 car freight trainthere should be about 7 tank cars .of all kinds - twoof which would be pressure tank cars. Trying toextrapolate the number of tank cars in an averagetrain to a predictable exposure factor becomesimpossible when one considers that a one freightcar derailment and a derailment involving fiftyfreight cars each count as a derailment. Mostderailments involve less than 5 freight cars and thederailments occur in all parts of the train length.Therefore one has 2/66 times x as the chance thata pressure tank car will be involved directly in aderailment where x equals the number of carsderailed.

It is extremely difficult to compile a meaningfulset of statistics from available sources becauseeach source has its own data base and interpret-ations of what constitutes failures or what evencounts as involvement. Another problem is findingstatistics covering the same time frame.

The National Transportation Safety Board onMarch 8, 1979 issued a report entitled "SafetyEffectiveness Evaluation of the Federal RailroadAdministration's Hazardous Materials and TrackSafety Programs". In this report statistics cover-ing all modes of transportation are covered for aseven year period from 1971 thru 1977. It showsthat during these seven years there were 71,917incidents reported involving hazardous materials,54,004 were on the highway; 12,215 on pipelines;4,850 on railroads; 610 in aviation; 158 on 'aterand 80 other.

The NTSB report shows that in 1977 there were 673train consists in derailments with 50,007 cars inthe consists (This equates to 74 cars per train thatwas involved in derailments). Of these 50,007 cars,3,118 contained hazardous materials; 949 hazard-ous materials cars were damaged of which 153released their contents. The release of hazardousmaterials resulted in 10,696 people beingevacuated. The derailments resulted in railroadequipment damage of over 29 million dollars.

In the above referenced report the NTSB con-cludes, among other things that "the FRA'smaterials safety program is fragmented andreactive without established goals, objectives, orcriteria by which success can be determined".

I'm in favor of abandoning these mathematicalgymnastics and even though I think the record fortank cars has been excellent when compared toother modes and other industrial experience letssimply agree there have been too many rail acci-dents involving tank cars and lets review what hasbeen done to improve safety and what still needs tobe done.

The AAR Tank Car Committee studies every majoraccident and a summary of all accidents to deter-mine if there are any specification changes thatcould be made that would minimize reoccurranceof the accident. They received a valuable assistfrom the AAR-RP1 Joint Safety Research Projectthat comprehensively studied all aspects of tankcar design.

A review of all the accident data revealed that thehead of a tank car was the most vulnerable areadue to punctures caused by couplers of adjacent

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cars. The most serious aftermaths of a derailmentinvolved head punctures of tank cars carryingflammable materials which when released thru thepuncture exposed other tank cars to a severe fireor direct torch which resulted in subsequent tankcar ruptures with disasterous results includingfatalities and heavy property damage.

Tests were run and it was determined that themost effective solution would be a coupler with atop and bottom shelf that would prevent disengage-ment of the adjacent car's coupler. In fact thecoupling was so good that it would break theadjacent coupler shank before disengaging and thuseliminate the coupler as a puncture source.

In addition and as an added precaution a 1/2 inchthick head shield has been installed on all pressuretank cars to further protect the tank car heads.This head shield may be an add on to existing non-insulated tank cars or may be a 1/2 inch thickjacket head on insulated or thermal shielded tankcars that are jacketed.

Existing ammonia tank cars of the 112A and 114AClass must now have these top and bottom shelfcouplers installed and head shields must beinstalled by Dec. 1980. A large percent havealready been retrofitted.

Flammable compressed gas tank cars of the sameclass must also be retrofitted -with a spray-oncoating or a jacketed thermal barrier that willprevent the tank shell from reaching 800°F whenexposed to a pool fire of 1600 F for 100 minutesand a torch fire of 2200 F for 30 minutes.

Many other specification changes have been madeby the AAR Tank Car Committee as a result oftheir studies of accidents. A few of which areoutlined as follows.

1. On stub sill cars it was required thatthe attachment of the structuralmembers of the draft sill to the rein-forcing plate be 85% of the attachmentof the reinforcing plate to the tank. Thisallows breakaway of the sill withoutdamaging the tank.

2. Interlocking couplers were required onall new tank cars effective January 1,1970.

3. The Committee required that gasketsfor manway coverplates and for mount-ing of fittings shall be asbestos type orapproved high-temperature resistantequivalent.

4. Pad requirements for brackets attachedto uninsulated tank car tanks wereestablished.

5. Safety relief valve venting arrange-ments were required to have sufficientopening in the bonnet cover to provideunrestricted discharge of the ventinggas for flammable compressed gasses.

6. Requirements were established forsumps and or syphen bowls on tank cars.

7. A new DOT paragraph 179.100-8 (b) wasproposed to incorporate a grain sizecontrol requirement for hot-formedheads.

8. A proposal was made to the DOT torevise paragraph 179.200-15 (b) of theDOT regulations as follows: "Manwaycovers must be designed to provide asecure closure of the manway. When ofthe hinged and bolted type using eye-bolts it must be equipped with amechanical interlock which will assurethat the internal pressure will bereleased before the cover can beopened".

9. Wording was proposed to the DOT forthe addition to sections 179.102-1,179.102-4, 179.102-18, and 179.102-19as follows: "Tank anchor to tank shellfillet welds must be examined by asuitable non-destructive testing methodto insure that welds are free fromcracks and other detrimental weld de-fects.

10. ASTM A240 Type 430A material wassuggested to be prohibited for construc-tion of tank car tanks for safetyreasons. DOT still allows this material.

11. The Committee proposed revisions toDOT regulations to require 12"minimum bottom outlet clearance, newand empty.

12. Paragraph C3-03, Figure Cl of AARTank Car Specs, was revised and DOTwas petitioned for revision of Part173.31 (c) (10) to require stenciling oftank cars with the date the test oftanks and safety valves is due.

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13. The TCC recommended to DOT theestablishment of 2% minimum outagefor domeless safety vent—equipped, nonpressure cars. Test results conductedby several tank car companies show areduced frequency of frangible discfailures due to surge in cars loaded to2% outage versus 1% outage. Discsettings for vents on non pressure carswere recommended to be raised to thetank test pressure.

1*. Paragraph AAR. 13-1 of the AAR TankCar Specifications was revised tostrengthen requirements for reinforce-ment at center sill cut-outs.

15. Paragraph A*. 10 was added to the TankCar Specifications, prohibiting gravityactuated vacuum relief valves on tankcars. These type valves are not capableof sealing in an overturn.

16. Revisions to DOT regulations were pro-posed for combination safety reliefdevices. The proposal would limit thesum of the start-to-discharge pressureto the safety relief valve and the burstpressure of the frangible disc to 75% ofthe tank test pressure unless a provisionis made to prevent any accumulation ofpressure between the frangible disc andsafety relief valve.

17. Tank cars requiring retrofit of headshields were handled on a service trialpermit basis. This was because theAAR Tank Car Committee was and stillis concerned that attachments for atleast one version of the DOT headshieldhad not had any service life experience.

18. Design requirements for manway coversfor non-pressure tank cars were revisedto make them stronger.

19. The Committee established designrequirements for bottom discontinuityprotective skids for pressure tank carsin the 112A, 114A, and 120A classesand also non^pressure tank car tanks.

20. Requirements for welded inserts in tankheads were established.

21. The TCC established - design and testrequirements for headshield attach-ments for DOT headshields.

22. It was required that a new pressure carsample line nipple must be made of Sch.80 austenitic stainless steel to mini-mize fatigue failures.

23. A commodity list of hazardousmaterials was compiled and compliancedates were established for bottom dis-continuity protection for each categoryof commodity. Cars used to transportthese commodities must comply withrequirements for bottom discontinuityprotection on stub sill, non-pressurecars after the dates that were estab-lished.

As you can see the tank car has been gone overfrom stem to stern in an effort to improve safety.

Unfortunately rail transportation safety is a twosided problem with tank car design being only one.The other problem being the cause of the accidentsin the first place. While I am qualified to speak toyou regarding tank car design I am not qualified tospeak on railroad operation. You need a railroadexecutive to speak on this subject.

Once a railroad accepts a tank car from a shipperfor delivery to some designated point the tank caris under the complete control of the railroads.There isn't anything you can do about it other thandesignate the route. If you know of some railroadthat has a bad safety record or whose employeesare careless, routing to avoid that railroad willresult in contact from the marketing arm of therailroad and perhaps some improvements can beinitiated internally within the railroad.

Mr. William H. Dempsey, President of the Associa-tion of American Railroads made a formalstatement in a NTSB hearing on April 5, 1978.Lets take a look at what he said the railroads aredoing to improve safety. His statement is far toolong to include intoto so I will be touching on onlyparts pertinent to this paper. It is suggested thatyou get a copy from the NTSB or AAR since it ispart of the public record if you desire more infor-mation.

The following is quoted from Mr. Dempseysremarks:

The railroad safety record — both in generaloperations and with regard to hazardousmaterials ~ is a good one. PreliminaryFederal Railroad Administration (FRA)figures indicate that total fatalities in rail-road accidents during 1977 were the lowest

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sines record-keeping began in the lastcentury. And 1977 was not an anomaly. Thenext lowest year was 1975 and the thirdlowest was 1976. From 1966 to 1976 — thelast year for which final figures are available— fatalities showed a 37 percent drop. TheBoard will note the data shows significantdeclines in all classes of fatalities —employees, grade crossing casualties,trespassers, passengers and others.

It is an ironic fact that at the same timedeath and injury rates were dropping, thenumber of reported train accidents has risen.This is a result, to some extent, of the kindsof accidents railroads have, the way theseaccidents are reported and the standards bywhich they are viewed.

The FRA categorizes accidents into threegroupings for reporting purposes; trainaccidents, train incidents and non-trainaccidents.

Train incidents refer to occurrences in whichthere was relatively little financial loss butwhich resulted in death or injury. As a resultof the changes in reporting criteria forinjuries beginning in 1975, (see footnote 1)the total number of incidents are now largerthan they were in earlier years. In 1976, thiscategory resulted in 1,299 deaths, the vastmajority -of which occurred at gradecrossings.-

Non-train accidents relate to injuries ordeaths../not involving the movement oftrains.—

Train accidents are the category whichreceive the most public attention. Suchaccidents may or may not involve injury ordeath — the reporting criterion is tied tofinancial loss. Since January 1, 1977, anaccident is a "train accident" if it involves atleast $2,300 damage to railroad property —whether or not it involved any injuries. Evena simple yard derailment — far less seriouspotentially than a truck tire blowout — canresult in costs that are this high. In 1975 and1976, the threshold was $1,750. From 1957through the end of 1974 — the only extendedperiod during which the data are comparable— the threshold for a reportable trainaccident was set at $750. Although the totalnumber of reported train accidents increasedby 57.* percent from 1966 to 197*, thisgrowth resulted partly because of expanded

operations and partly because inflationcaused mishaps to be reported which wouldnot have been included in the numbersbefore. Taking those factors into account,the increase over the nine-year period was15.9 percent.

In 1976, there were 10,2*8 train accidents.Approximately *2 percent of these accidentswere caused by defects in track orstructures, 21 percent by equipmentproblems, 23 percent by human factors and1* percent by other factors. Deaths in thiscategory totaled 158. Stated another way,train accidents accounted for only about 9percent of total deaths.

Of those train accidents, 7,93* were derail-ments. The average monetary damageincurred in derailments was $23,226 — lessthan the price of one new freight car. .OnClass I railroads, there were 7,658 derail-ments. Of these, only 381 involved damageof more than $100,000. Only 115 of thatnumber involved damage of more than$250,000 and only 2* of that number involveddamage of $500,000 or more. Such a greatdifference between the most costly accidentsand the average cost indicates that the vastmajority of derailments are indeed not veryserious in monetary terms.

Moreover — and more significantly — if theinflation factor is removed by applying 1976dollars to the cost of derailments on Class Iroads from 1966 to 1976 it can be seen thatthe number of serious derailments — thoseinvolving the most property damage — andthe most serious threat of death and injury —has dropped substantially in recent years.

I have not made this explanation for thepurpose of criticizing the FRA or its report-ing standards. Obviously, some criteria mustbe applied. But, if the criteria are not fullyunderstood, one reading them could easily geta totally false picture of the trends in rail-road safety.

Let us turn now to the subject of railroadtransportation of hazardous materials -~ asubject of much attention in the wake of therecent tragedies.

It is important to remember that greatamounts of these materials are carried byrail,, not despite the fact that they arehazardous — but rather because of it. Rail-

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road carriage of hazardous materials is,generally speaking, the safest mode of transitfor these substances necessary to every daylife and commerce.

In recent appearance on television's "GoodMorning America", James King, chairman-designate of the National TransportationSafety Board, noted that about 2.4 percent ofall transportation accidents involvehazardous materials. However, he said that91 percent of those accidents, 75 percent ofthe injuries and about 80 percent of thefatalities occur on the highways and involvemotor vehicles.

It would follow from this assessment that lessthan 9 percent of all accidents involvinghazardous materials occur in rail transpor-tation. Yet, according to the Department ofCommerce's 1972 Census of Transportation —the most recent available - - more than 40percent of all tonnage of major hazardousmaterials, excluding petroleum, moved byrail. Since the railroads have a higher shareof the longer movements, 70 percent of thetransportation (ton-miles) of these productswere provided by rail service.

According to a report by the Secretary ofTransportation on Hazardous Materials Con-trol, the years 1975 and 1976 saw a total of45 deaths resulting from the transportationof hazardous materials. Of these, twooccurred on the railroads. The other 43occurred in movements by private and for-hire highway carriers.

Let me emphasize that I am neither trying totransfer attention to the motor carriers,which operate in a more uncontrollableenvironment, nor am I trying to wipe awaythe deaths that occurred this year. But Ithink these figures illustrate the thesis withwhich I began this discussionr

First, that it is necessary that hazardousmaterials be transported, and, second, that —in an imperfect world ~ railroads aregenerally the safest way to transport mostsuch materials.

In 1976, more than a million carloads ~ about80 million tons ~ of materials classified ashazardous traveled by rail. Most suchmaterials traveled in tank ears.

There are 170,000 tank cars in the nationalrail fleet, of which railroads own only about2,675 — about 1.5 percent of the total. Themajority are owned by private non-railroadcompanies.

Of the million carloads which moved by railin 1976, only 150 were involved in accidents,and, of the million, 11 cars had violent rup-tures.

Because of the potential for disaster inherentin the movement of hazardous materials, therailroads are not complacent about theirrecord simply because it is good in compari-son with highway movements. We devote agreat deal of attention to this subject in theAssociation of American Railroads.

I would now like to turn to the question ofaccident causes. The recent derailmentssparked, in many minds the immediate con-clusiuon that decrepit track on the nation'srailroads had created an extremely unsafecondition. As I have demonstrated, the firstfault in that conclusion is that railroad safety~ in terms of human safety — is improving,not deteriorating.

The second fault is that track conditions havenot been the cause of most serious railroadaccidents involving hazardous commodities.They were not, according to the preliminaryfindings of this Board, the cause of the tworecent tragedies —unless one would stretchthe term "track conditions" far enough toencompass sabotage.

i will certainly not deny that some railroadshave sections of track which are in less thansatisfactory condition. This has generallybeen the result of serious financial problemsaffecting the railroads which own the track.However, not all railroads are in suchfinancial difficulty. Railroads in the Westand Southeast are, in the main, relativelyprosperous and the condition of their main-line track reflects their ability to finance thenecessary levels of maintenance. Somecarriers in the East have also been able toavoid the problems besetting bankrupt andmarginal carriers.

However, there is no demonstrable signifi-cant relationship between the frequency ofmajor accidents and either the financial con-ditions or maintenance levels of particularroads. The explanation for the seeming

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incongruity lies in the operating practicesadopted by the weaker railroads.

All railroads attempt to protect employeesand cargo as well as to minimize thepossibility of accidents by adjusting trainspeeds to take known track conditions intoaccount. This has become a frequentpractice on bankrupt and marginal railroadswhich are the least able to afford the lossesinherent in a major accident. These speedreductions can have a very adverse effect onservice and operating costs, and accordingly,they represent a major competitive drawbackin an interdependent industry in which anestimated 70 percent of total revenue involveshipments over two or more railroads. Unlessthe earnings of these companies are sharplyimproved and the repayable financingprovided by the Congress under the 4-R Actfully distributed, it is doubtful the estimated$4 billion in deferred maintenance can bereduced significantly.

At the same time, these deficiencies havenot led to an increase in major accidents. Infact, several industry safety awards havebeen won by some of the most financiallypressed railroads in recent years.

To examine the relative frequency of acci-dents and derailments oh the so-calledweaker railroads, we have examined all trainaccidents and all derailments involving ClassI railroads for the 11-year period, 1966 -1976,which would have qualified as reportableaccidents jjnder the FRA reporting Criteriain 1976.-' The total accidents andderailments for all Class I carriers wereadjusted to restate the property damage interms of 1976 dollars throughout the periodand the results were then compared withsimilar statistics for seven bankrupt carriersand ConRail. -'

The selected carriers, which provided 17 per-cent of the total gross ton-miles of passengerand freight service, were responsible for 22.5percent of all accidents and 23.8 percent ofall derailments in this period. Throughoutthis period, these selected carriers accountedfor a higher percent of the industry'saccidents than they did of total operationsmeasured in gross ton-miles.

However, a more important observation isthat these same financially troubled carrierswere responsible for a smaller percentage of

derailments involving major property damagebetween 1966 - 1976. With 17 percent of theGross ton-miles of operations during theperiod, the eight bankrupt carriers had 16.7percent of the derailments involving $100,000or more in property damage, 15.5 percent ofthose over $250,000 and 14.5 percent of thoseover $500,000.

From 1971 through 1976, the excellent recordof these marginal carriers is morepronounced. With 15.9 percent of theindustry's gross ton-miles in those six years,these carriers had only 11.9 percent of thetotal derailments over $100,000, 8.5 percentof those over $250,000 and 6.2 percent ofthose over $500,000.

There has been a decline in costly derail-ments for the industry as a whole in recentyears. From 1966 through 1976, derailmentscausing over $100,000 (1976 dollars) declined14.8 percent, those over $250,000 dropped45.8 percent and those over $500,000decreased by 64.7 percent despite trafficincreases.

In short, the number of costly derailmentshas shown a consistent downward pattern forall major railroads, with the most financiallypressed carriers registering fewer suchaccidents than the industry average.

Turning again to the movement of hazardousmaterials, we find a similar lack of correla-tion between major accidents and thefinancial condition of various railroads. Anexamination of the 15 most serious accidentsfrom 1969 through 1975 involving the move-ment of dangerous substances shows causesthat virtually defy classification ~ but onlyone was definitely attributed to track by theNTSB.

Only two of the major accidents took placeon those railroads — bankrupt or marginal —which (at the time of the accidents) ranked inthe lowest third of all major railroads interms of earnings. Four occurred on theproperties of railroads which ranked in thetop third and the other nine involved rail-roads in the middle of the industry's financialspectrum. The same general distribution ofaccidents is- found when these 15 majoraccidents are classified in terms of the levelof track maintenance.

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I would like to make clear, however, thatrailroads have not been ignoring trackproblems. There are instances of deferredmaintenance by financially pressed railroads,to be sure, but industrywide spending forcapital improvements and maintenance are atrecord levels.

In 1976, spending for these purposes reachedmore than $8 billion and this was topped in1977 by a new alltime high of more than $9billion. And I should point out that thesespending records were achieved in the face ofindustry earnings which for the past threeyears have been the lowest since prior toWorld War II.

In 1977, railroads invested $3.3 billion formaintenance of way (track, roadbed, andfacilities), a 50 percent increase from the$2.2 billion spent in 1975. Expenditures lastyear for equipment maintenance were $2.9billion, up 40 percent from the $2.2 billioninvested in 1975. (These advances cameabout as the result of higher spending in allthree railroad territories.) And capital ex-penditures for non-equipment projects in1977 reached another all-time mark — $750million, a 54 percent increase over '75.

The industry's latest figures (through 1976)show that 27 million new ties were installedin 1976. That's the most in 20 years, repre-senting a 35 percent increase over theaverage of the past 10 years. Some 802,000tons of new rail were laid in 1976, again thelargest amount in the past 20 years and 33percent more than-the past ten-year average.Figures for 1977 are expected to equal orexceed these results.

To help provide a smoother ride and greatersafety, some 55,000 miles of welded railswere in service going iato 1978. This repre-sents about half of the mainline in theindustry, and installation is continuing at therate of approximately 4,000 miles annually.Welded rails eliminate the wear factor atjoints which is present when sections of railare laid end to end and bolted together.

The Office of Technology Assessment hasrecently released an evaluation of railroadsafety. We generally support the findings ofthis study, particularly statements which say,basically, that the regulatory activities ofthe Federal government have not, apparently,had any effect on the railroad accident rate

and may, in some instances, have been coun-terproductive.

We can also easily agree-with a finding that"Because of the complex nature of the rail-road system, continued cooperation amongconcerned parties is essential if furtherefforts to reduce safety losses are to occur."

A few years ago, the National TransportationSafety Boaird, in analyzing projected freighttraffic volume in 1980, estimated that a 4.4percent increase in the railroads' share oftraffic, and a comparable decline in trucktraffic, could mean a saving of 533 lives and7,302 injuries in that year alone.

This is a testimonial to the comparativesafety of railroad freight transportation»Proof of further improvements are offered bythe industry's declining fatality rates andrapid escalation in track maintenanceprograms.

I would like to remind you that railroadsafety is not a subject which has languishedin obscurity until brought to the forefront bymajor accidents. The railroad industry, incooperation with allied industries, laborunions and the Federal government, hasdevoted significant amounts of time, moneyand manpower to studies and programs aimedat improving safety ~ both in terms ofhuman life and the cost of accidents. Thetank car program which I have discussed, amajor research project on track-train dynam-ics, a locomotive cab safety program, a gradecrossing inventory — all are examples ofefforts initiated by the railroad community.

That the subject continues to commandattention is demonstrated by the OTA study --undertaken long before the recent accidents— and by these National TransportationSafety Board hearings.

The railroad industry also intends to continueto cooperate with the Federal RairoadAdministration in its efforts to promotebetter safety on the nation's railroads.

We believe these intensive activities, alreadyin motion, can expand the progress that hasbeen made once the necessary, thorough andimpartial analyses are completed" Unquote.

So now you have heard from the tank car and therailroad points of view. As you can see both are

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diligently working and have pledged to continueworking to improve tank car rail transportationsafety.

There is something you can do from your ammoniaplant level, and that is to help insure that the tankcar when loaded and ready to be picked up by therailroad is in good operational condition. How toconduct this pretrip inspection is covered in appen-dix A. I urge you to read and study Appendix A andput it into effect in your plant.

In closing there is one other important point I wantto impress upon you;

At some time in the future you may be called tothe scene of a bad railroad derailment and askedfor advice. In addition to your training regardingwhat to do in case of leaks or fire, resist allattempts by the uninformed to shoot holes in thetank cars or blow them up. Extremely seriousconsequences could result. Not long ago in Canadaan explosive charge was placed on a wrecked tankcar and when it blew a hole in the tank, the tankcar took off like a rocket leveling utility poles,houses, trees and everything in its path.

It has certainly been a pleasure to appear beforethis AIChE Symposium on Ammonia Plant Safetyand I hope I have provided you with some food forthought and that I have successfully enlisted you inthe army of individuals constantly striving toimprove tank car safety.

2/— Fatalities at grade crossings have alsobeen dropping. Preliminary FRA figuresshow the 1977 toll down 47 percent from the1966 total despite substantial increases inhighway traffic.

- Such accidents claimed 227 lives in 1976.

5_/ In effect, this adjustment eliminatescertain inexpensive accidents in earlier yearswhich would not have been reported in lateryears even if they were increased to reflectinflation. The adjustment thus places acci-dents on a constant dollar basis consistentwith the 1976 criteria.

6_/ These railroads are the Boston and Maine,the Central of New Jersey, ConRail, ErieLackawanna, Lehigh Valley, Penn Central,Reading and Rock Island.

APPENDIX A

PRETRIP INSPECTION OF TANK CARS

In preparation for rail shipment AnhydrousAmmonia must only be loaded into DOT authorizedand properly marked tank cars. An inspection ofthe car before loading is needed to determine if itis a proper car. Such an inspection would be asfollows?

Looking at the side of the tank car, the firstmarkings are on the left. These are the reportingmark and number. These identify the tank carowner. For example PSPX 30100 would be aPhillips Petroleum Company privately owned tankcar. The first three letters signify the owner andthe X depicts that it is privately owned. Next arethe markings relating to the weight of the car.The first is the nominal capacity and the next isthe light weight of the car. This light weight mustbe added to the weight of the product loaded toinsure that allowable gross weight on rail will notbe exceeded.

Additional markings appear on the right side of thecar. These include the name of the specificproduct loaded. The commodity marking isrequired for anhydrous ammonia and for otherproducts as spelled out in the regulations. Extremecare must be taken to assure that the productloaded and the commodity marking are the same.Next we come to the tank car specification. Bythis is meant the number of the DOT specificationto which the car is built. This number must bechecked to make certain the tank car specificationis authorized for transporting anhydrous ammonia.

The cars must have a 105, 112, or 11* numberwith 300 pounds or more test pressure.

The next area is reserved for the safety reliefdevice information. This shows the pressuresetting of the safety relief device, along with thelast test date.

Since September of 1976 all cars that are shippedfor retest must be marked with the test due date.The safety relief device must be periodicallyretested every five years. The test due date orlast retest date will alert you when a car is not incompliance. Do not load car if retest is overdue.

Next is the tank test pressure and date of test.DOT regulations also require periodic retesting ofthe tank itself. After September 1976 the testdue date must be shown when the tank is retested.The same check for compliance must be madehere. Retest of safety valve or tank may be madeat any time during the calendar year in which thetest is due.

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When you have determined the car to be loaded isa proper specification and all tests are incompliance, the tank car itself should beinspected for defects. A walk around inspectionis desirable. The inspection should be made forobvious visible defects to the safety appliancesand running gear, and it is normally performedbefore a car is loaded. If defects are found, theinspector should report to the proper authority,tag the_defect, and the car should not be loadeduntil repair is made. As mentioned previously,certain types of damage caused by improperhandling by carriers are railroad-responsibledefects. A dent to the tank sides or heads orindentations caused by wheels are examples ofrailroad responsibility. Dented bent jackets arenot the railroad's responsibility and should bereported to car owner. If a defect is found forwhich the railroad is responsible and no defect cardis found in the holder, contact the delivering railcarrier and secure a defect card properlycompleted and signed. Do not load the car.

This inspection is the . responsibility of the railcarrier, but when, duplicated by employees of theshipper, it provides an important extra margin ofsafety. If any defects are noted, they should bereported to supervisory personnel and the localrailroad inspector, freight agent, or switchingcrew.

The approach ladders to the safety platform andwalkways should not be bent, deformed or havemissing rungs. There should be clearance of atleast 2 1 / 2 inches between the center line of aladder rung and the tank side. An obvious defectwould be if you were unable to put your foot on arung of an approach ladder. The ladder should alsobe securely fastened at top and bottom, and thereshould be no loose bolts or rivets.The sill steps are also required to be securelyfastened and not bent in or out more than 3 inches.Also, the hand holds or hand rails on the sides ofthe car should not be loose, bent or broken.

Depending on the severity of the defect, the carmay have to be forwarded to a tank car repair shopor railroad repair track for repairs.

In any case, plant or railroad personnel are notpermitted to perform any welding repairs on thetank. This type of work must be done at anauthorized AAR repair facility by a qualifiedwelder in accordance with authorized procedures.

The sill plate welds should be examined for crackswhich may occur at points of greatest stress. Oneexample is the point where the bolster support andend sill join the center sill. Any bending or bowingto the sill plate should require that the car beremoved from service for repairs by the railroadinspector.

The linkage of the brake assembly should be in-spected for missing, loose, broken or inoperativeparts. Cotter pins should be in place or the linkagewill vibrage apart and cause the entire system tobecome inoperative.The air brake cylinder should also be checked todetermine that it is firmly bolted in place andthat all piping connections are secure.

Brake Shoes missing, cracked or worn too thinshould be reported for railroad action. Metalshoes that are less than 1/2 inch thick orcomposition shoes that are less than 3/8 inchthick should be reported as needing replacement.

If the brake shoe key is missing the shoe can falloff, then when the brakes are applied wheels maybe scored and ruined.

Another part of the brake assembly that should bechecked is the hand brake wheel. When the handbrake is released, the chain linkage should notdroop and rub on the axle. The air brake hosesare an important part of the braking system andshould not be cracked, broken or missing.

Truck springs should be examined. Broken, mis-placed, or missing springs must be reported andrepaired by the railroad. If flat surfaces arenoted on spring coils they should be reported.This indicates the springs are too weak and thecar is bottoming out in transit. This defect willcause road shocks to be passed directly to thetank. Over a period of time, it can cause veryserious stress damage to the tajik itself.

If the car is equipped with roller bearings, checkthat the three retaining cap screws are in placeand tight and that there is not leakage of lubrica-tion. The retainer keys should be bent up toprevent movement of the bolts caused byvibration in transit. Loose or missing cap screwsshould be tightened or replaced.

Cars with friction type bearings will have a lidand a container of lubricating oil and lubricatingpads. Check for loose, bent, or missing lids or nogasket on the lid. It is the carrier's responsibilityto add the necessary amount of oil at eachinspection point. Sand, water, or metalcontaminated oil or unlubricated pads requireimmediate attention by the rail carrier.Overheated journals (axles) can be spotted by thetell-tale sign which is a blue discoloration of theaxle. In all cases these cars should be reportedimmediately and taken out of service.

All wheels on the car should be examined forcracks or chips on the flange or tread. Heavilyworn grooves or "thin flanges require replacementby the carrier.

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A recent problem of cracks appearing in the centerplate weld attachment has shown that the railroadinspectors are not always finding them in theirinspections. These cracks when present are verydifficult to find because of the congested area inwhich the center plate is located. The position ofthe tank after the car is stopped can affect thecrack opening and make it more visible. Shipperscan unofficially assist the railroads by including aflashlight inspection in this area in their walk-around observation as a check on the adequacy ofthe railroad inspection.

A crack in the weld that extends more than 20inches along the circumference or a crack or chipto the edge of the bowl on the truck itself requiresthat the car be removed from service immediatelyand forwarded to a repair shop. A crack of anylength in a weld or in the plate itself should bereported to the supervisor for corrective action.

The coupler face should open and close freely whenreleased. Look for cracks in the coupler horn alsolook for a drooping coupler which can causeaccidents in transit and which must be correctedimmediately by the carrier.

Except in those areas indicated, these items cannormally be handled at the local carrier repairtrack. Repairs to springs, brake rigging, wheels,couplers, and striker plates are considered AARtype repair items. Carriers will perform theserepairs and invoice the owner of the car in accord-ance with standard costs established by theAssociation of American Railroads.

When the walkaround observation is completed, thetank fittings must be examined for leakage. Thisexamination is the sole responsibility of the loadingrack personnel.

Before you climb to the manway safety platform,visually inspect the platform to ascertain that theapproach ladders, hand rails and platform itself arenot broken or corroded. A few minutes of extracaution devoted to this inspection can go a longway in preventing accidents.

When you check the protective housing cover, lookto see if it has a seal attached to the pin. If itdoes, the seal should be broken and examined tosee that it agrees with what is shown on the returnbill of lading. Then, examine the interior of theprotective housing.

All fittings must be operable and each one sealedwith a plug or flange that is fastened securely tothe valve or the cover plate with a chain. The

safety relief device should be examined to seethat there is no blockage to the relief opening.And, of course, make certain that there are nosigns of leakage.

One of the major trouble spots in this operation isthe slip tube gaging device. Make certain thatthe packing gland on the stem is in good conditionand that the packing gland nut is tight enough toprevent leakage and yet allow rod operation.

Before each loading, all valves and fittings in thetank car dome should be inspected for leaks ordamage. Loading points should be equipped tohandle minor repairs on, or replacement of, valvesand other fittings in the domes of these cars.

After the tank car is loaded, replace all pipe plugsin eduction and vapor valves and tighten with apipe wrench. Close the protective housing coverand secure with a locking pin. Apply seal toprotective housing locking pin and apply therequired DOT placards in the metal holderslocated on each side and each end of the car. It isabsolutely essential that the correct placards beused.

Remember that it is illegal to ship a defective orleaking tank car. The consequences or failure toprepare a car properly for shipment are verysevere. Violations of the Code of Federal Regula-tions can carry fines of up to $25,000 or fiveyears in jail or both. The protection of life andproperty, however, is even more important. It'sup to you to make certain that all necessaryprecautions are taken to safeguard the public,yourself, your fellow workers, and theenvironment.

These tank cars are an essential link betweenammonia producers and their customers. I do nothave to tell you how important ammonia is to oureconomy nor to the well being of the public. Thefact remains though that in spite of all thebenefits that acrue to the general public from thedistribution of anhydrous ammonia, unfortunatelysmall portions of the same general public aresometimes exposed to the disadvantages ofunintentional and premature release of ammoniacaused by accidents of one kind or another. Mostunfortunately some lives have been lost in theseaccidents. With the value of life being sacred itrequires that the safe handling of ammonia andammonia transportation equipment be uppermostin our minds. This is what this paper is all about.

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DISCUSSION

JOHN LAWRENCE, C.F. Industrio«: I've seen a lot oftank car wrecks. I don't think I know much aboutthem. If you go out to where an ammonia tank car isturned over—it's laying out there full of ammonia—what do you personally recommend that one does?You don't know whether there is any serious damageto the tank car. Possibly the railroad can set it backon the tracks and move it out of the area. What doyou do when you go out and see one of those thingslaying there?HELLER: The first thing is to conduct a walk aroundinspection to determine just how badly damagedthe car might be, particularly looking for dents andgouges that might cross some of the welds andcause a serious cold worked area. If there are nocracks or leaks, recommend that thé tank car beunloaded as soon as possible, preferably before it iseven moved. It is also preferable to unload it in theevening when the temperature is coolest. Therehave been a couple of very serious accidients. Whenthe tank car which had some mechanical damageundetected, was not unloaded promptly and theweather warmed up from a cold winter temperatureto a 50° afternoon temperature, the increase inpressure in the tank caused the tank car to rupture.So, it is very important to get the tank car unloaded asquickly as possible. If it cannot be unloaded, one musttake steps to keep the tank car cool.JOHN BLANKEN, UKF, Holland: I fully agree with yourremarks about not always relying on excess flow valvesthat are installed on tank cars to protect against loadingline failures. We operate a road tank and loading stationwhere we take ammonia from a sphere under 7-atm.pressure. We have a loading front with a head of 2-atm.We go from a loading bar to a road tanker. The vapor

space of the road tanker is connected to a gas holder.We find that if you decrease the pressure in the gasholder connected to the road tanker, the ammonia flowgoes down instead of up because the loading arm gets atwo-phase f tow and starts choking. We realized that. Wealso realized that if the loading arm would fail upstreamof the fixing arm normally, it would insure that the excessflow valve would see more liquid flowing through itunless two-phase flow in tie. loading arm causeschoking. We are already conducting experiments of theloading of the road tanker; we are doing some computercalculations with two-phase flow through lines like that.But, I fully agree that one should not rely on an excessflow valve in the road tanker to protect one.againstdispersion of ammonia, in case the loading lines fails.HELLER: Normal practice in the United-States is toconnect the storage tank and the receiving tank toequalize pressure and not to create a pressuredifferential to assist in the unloading. By doing thisand unloading with a pump, it can be difficult to gettwo-phase flow in the unloading line because theliquid deduction line has a pipe that goes to thebottom and it is only in contact with liquid.BLANKEN: I'm not sure of that answer. I will try torepeat the point I tried to make. It has been found indealing with saturated water that if you have asharp-etched orifice, its flow through that orifice tobe calculated has to be liquid water. That means youhave a large flow, if the line close to the rail tankerbreaks. If you have a low-pressure line receivingtank and the line to it fails downstream after theexcess flow valve, you get turbulent velocity and thetwo-phase flow in the line.HELLER: That is correct.

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