Wood about 25 year and they can be changed 1 out of 5 ties every 5 year so cost is spread out.
Plastic or composite ties are 50 years plus and same as wood tie replacement just bad once or cyclical, they can be mixed with wood.
Concrete ties last about 60 years if traffic is low, but in wet or wrong ballast conditions bottom gets chewed up and ties break at rapid rate..
When Concrete ties are used all ties need to be replaced with Concrete , you can't mix them with wood or plastic.
With Concrete ties weighing over 200 pounds the insertion of ties needs to be done with mechanised equipment that shortlines do not have. It realy ads to cost if outside contractors need to be brought in, and a BIG investment has to be made with a long time depreciation.
If Conductors are in charge, why are they promoted to be Engineer???
Retired Triebfahrzeugführer. I am not a moderator.