Bump Posts or Wheel Stops?

[Anonymous]

When should a dead end track end in a bump post... and when a set of wheel stops? I'm trying to work out whether there is any pattern in which gets used where before I model them.

[TomDiehl]

A couple VERY general rules:

The wheelstops are used when they need 1) clearance above the end of the rails, for example a loco pilot in the roundhouse. 2) A temporary stop, the wheelstop is just clamped over the end of the rail (or wherever needed).

The bumping post is used when a more permanent or more solid stop is needed. A car at a good roll can jump over a wheelstop, but a bumping post is more likely to stop it, with of course, damage to itself and the car. Most of the time a "lesser of two evils" thing, like a derail.

[tstage]

Tom,

Ooooo...Oo..Oo...[D)] Stupid question time. [D)] May I ask one?

I've always wondered but never have learned: Why and for what reasons is a derailer used in certain situations? Besides derailing a boxcar or locomotive to remove it from the tracks, why else would you want to in the first place? Thanks.

Tom

[TomDiehl]

A derailer or simply, a derail is a final level of protection. The installation usually has them on the siding or spur far enough away from the main route so that if a car on the siding rolls away, when the car rolls over it, it will derail it to prevent it from rolling onto the main, possibly causing a serious accident. As I said, a "lesser of two evils" type device. A LOT easier to rerail one car than to clean up a major wreck.

[jimrice4449]

One thing to watch if you ever want to model a derail. It goes on the rail AWAY from the track being protected so as to derail away from the protected track. This assumes you're talking about the steel casting that lifts on a pivot to sit on the rail. There were also split rail derails which are essentially a set of switch points w/ no frog. These were typically used at interlocking plants and at the approach to lift bridges.

[nbrodar]

Derails are also used to protect tracks were there are locomotive machinists, car inspectors, track workers/equipment, cars being loaded or unloaded and occupied camp cars. Obviously, you don't want anything rolling into these tracks. Moveable bridges have derails, as well, because trains in the river are bad.

Nick