Salient. Victoria University Student Newspaper. Volume 36, Number 9. 1ts May 1973

Train Derailment

Train Derailment

A number of factors influence train derailment. Security measures, such as patrols and track walkers, may be expected wherever there is resistance; activity. Mountainous terrain offers steep grades, sharp curves, bridges, culverts, and tunnels which are ideal locations for derailment. In other areas a long level section of track may be the only vulnerable point, and it is suitable if the train moves through the area at high speed. Derailment on double-track lines should be accomplished on curves to that a single train will obstruct both tracks. Three derailment techniques are described in this section.

a. Technique. 3-5-2 (fig. 24). This method uses three charges weighing 1.25 kilograms each, placed and tamped under every fifth crosstie.

(1) The charges are linked together with detonating cord. A firing device with detonator is taped to detonating cord leads on both ends of the chain. The charges may be detonated from either end by an electrical firing circuit or by a pressure device actuated by the weight of the train wheels. The detonating cord should be extended on each end of the charges for a distance of at least 10 meters. The firing device should be placed at the end of the detonating cord nearest the approaching train. This is to insure that the charges blow in front of the train and not under it. The charges are placed under their respective ties and firmly tamped into position. The explosion will remove the rails at least 1 meter beyond the outside charges, disrupting at least 6 meters of rail. Additionally, the ties are broken and a crater is formed.

The depth of the crater depends on the type of ballast material in the railbed. Since the charges are not placed in contact with the rail, the rail is lifted upon detonation. The pressure breaks the rail just beyond the outside charges.

(2) The disadvantages of this technique are the time required and noise associated with the placement of the charges. Once the charges are cm placed, they may be left in position for extended periods.

b. Technique, 10-2-1 (fig.25). This method uses a total of ten 0.5 kilogram charges, each charge placed against the rail over every second crosstie.

(1) The charges are linked together with detonating cord. The charges are wedged or lashed to the web of the rail directly over the crossties. Detonating cord priming leads must extend from both ends of the chain. A pressure firing device may be used.

(2) The advantages of this technique are speed and silence in emplacement. The disadvantage is that the charges are visible to trackwalkers.