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Derailment Survey

Tell us what you've found to be one cause of derailments and what was done to correct the problem.

Derailment cause

Derailment cure

Broken Switch

Fixed Switch

rotted ties

move screws

Most track related derailments are caused by track cross-level problems

Check derailment area with spirit level adjust and re-tamp.

Too much clearance between bolster and outboard bearings of cars

Use the three point suspension technique making one end of the car flat on the bolster and give the other end +/- 1/16" clearance between car outboard bearings and bolster.

low rail joint

tighter rail joint, place tie under rail joint and tamp ties under rail joint.

derailment on outside curve rail

raise outside rail...maybe even super elevate slightly

parallel rail joints

stagger rail ends at least 18 inches

rolling stock side frames too stiff

drill and place round head bolt or rivet on top of bolster

couplers don't have enough side lateral movement

replace center sill or shave sides of coupler shank to allow more side-to-side movement

when no fault of track can be located, examine wheel axle assemblies.

replace axle and press wheels on

sharp flanges climb outside rail on curves and/or rail joints

make sure flanges are well rounded and there is a fillet between the wheel tread and flange

Passengers leaning or shifting.

Watch and warn the passengers as well as possible. Moderate speeds in case a derailment does occur.

low joints in a curve after frost has left the ground and a "tight" bolster

I have to raise the joints and keep checking them as they tend to settle after a while. With the bolster I increased the washer thickness on one bolster.

Not enough vertical movement in the coupler links

Made new coupler pockets with 2 times the movement

springs in trucks too powerful reduce number of springs in trucks or replace with weaker springs
A long train (over 7 cars) can  buckle when using independent brakes; thus causing a derailment. use caution when going downhill.
Not having the very same radius at ends of curved rail joints. Re-adjust the radius.

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