APPENDIX A

INVESTIGATION

The National Transportation Safety Board was notified of the accident about 9 a.m. on April 8, 1979. The Safety Board immediately dispatched an investigator from its Atlanta field office and an investigative team from Washington, D.C. to the scene. Investigative groups were established for operations, equipment, track and structures, and hazardous materials.

APPENDIX B

LOUISVILLE & NASHVILLE CREWMEMBER INFORMATION

TRAIN NO. 403, APRIL 8, 1979

Engineer Ernest E. York, 52, was employed as a shop laborer on July 3, 1943. He left service on August 8, 1944. He was re-employed in engine service as a fireman on June 14, 1952, and was promoted to an engineer on February 5, 1958. He passed his last medical examination on April 17, 1978, and his last operating rules examination in September 1977.

Head Brakeman John L. Durgins, 51, was employed as a freight house laborer on December 16, 1943. He left service on June 6, 1945, and was re-employed as a section laborer on May 26, 1947. He transferred to train service as a trainman on August 3, 1974. He is presently qualified as a trainman only.

Conductor Wayne Johnson, 49, was employed as a brakeman on March 14, 1951. He left service to serve in the armed forces, on December 21, 1951, and returned to work on January 25, 1956. He was promoted to conductor on May 20, 1966.

Rear Brakeman Michael McKinley, 31, was employed as a trainman on January 16, 1970. He was promoted to conductor on November 11, 1972.

As the total strength of a chain is limited by the strength of its weakest link, so is the ability of a freight train to resist high drawbar forces limited by the weakest draftgear component.

The principal draftgear components are the couplers, knuckles and yokes. Of these, the weakest element is generally the knuckle. It is also noteworthy that the knuckle has been designed intentionally in this manner, since it is the most easily replaced item.

Knuckles and couplers are manufactured in three categories: Grade B, C, and E, having ultimate tensile strengths of 350,000, 550,000 and 650,000 lbs., respectively. As Grade B knuckles are commonly applied to interchange cars, this type of knuckle is taken as the limiting factor in determining the maximum power requirements. The exceptions involve such cases as unit trains in operations where the railroad may elect to install stronger draftgear components to permit a more massive concentration of locomotive power.

When starting a train a typical single 6-axle locomotive unit can develop approximately 100,000 lbs. drawbar pull. However, a 70,000 lb. limit is generally accepted by the industry and is used in rating this class of power in train operations. This level of drawbar pull (i.e., tractive effort minus locomotive resistance) is developed for a full throttle setting and a speed of 12 mph. Four such units would develop about 280,000 lbs. of drawbar pull. In grade territories where more than three 6-axle units are used in multiple, cars immediately behind the locomotive consist should be equipped with higher-strength knuckles.

Thus the knuckles and couplers on the first car must withstand the steady state drawbar forces of the locomotive, plus the additional dynamic slack action generated by jerk forces, wheelslips, etc. From the above data it can be readily seen that knuckles and couplers can be subjected to draft forces in excess of 250,000 lbs., without even considering the dynamic effects of slack action.

The following graph (figure 15) was prepared to illustrate the allowable trailing tonnage for various compensated grades at designated speeds so that the resulting drawbar forces will not exceed 250,000 lbs. The train resistance was calculated using the Davis formula for freight cars:

R = 1.3 + 29/w + 0.045V + 0.0005AV2/wn

where R = resistance (in lbs/ton) on level tangent track

w = unit weight per axle (in tons)

n = number of axles per car

A = effective cross sectional area of car (in square ft)

V = speed (in miles per hour)

The grade resistance (in lbs/ton) is 20 times the percentage of grade.

A pragmatic factor of 0.80 on the graph is applied to the trailing tonnage to allow for adverse operating conditions such as: weather, weak knuckles, yokes and couplers, grade discrepancies, train surges, rail inequalities and slippage due to curve oilers.