scale operating of a locomotive

[Piyer]

one thing barely touched upon here is coupling cars. the impact force increases with the square of the impact speed, thus it rises exponentially with speed. most railroads have rules on how fast you can couple into cars "no more than 4" is a saying I have seen used.

From the NY&W's Employee Time Table #29 (April 28, 1957):

Rough Handling
Impact shocks or energy possessed by a fifty ton car loaded to capacity, moving at different speeds or velocity.

MPH / Impact shock energy in foot pounds / Times shock increased
1 mph ---- 4,785 fp ---- 0
2 mph ---- 19,140 fp ---- 4
3 mph ---- 43,095 fp ---- 9
4 mph ---- 76,594 fp ---- 16
5 mph ---- 119,598 fp ---- 25
6 mph ---- 172,381 fp ---- 36
7 mph ---- 234,598 fp ---- 49
8 mph ---- 306,431 fp ---- 64
9 mph ---- 387,858 fp ---- 81
10 mph ---- 478,490 fp ---- 100

A.A.R. minimum draft gear absorption 18,000 foot-pounds

[Desertdweller]

Roger,

Not all sidings and secondary tracks are built downgrade from main line track.  This is what derails are for.

I have never seen operating derails on a model railroad, although a split-point derail could be made easily from a turnout.  It could even be power-operated.

Split-point derails are fairly uncommon on the prototype.  "Flop-over" derails are common.  Their small size would make them difficult to model.

Les

[rogertra]

Roger,

Not all sidings and secondary tracks are built downgrade from main line track.  This is what derails are for.

I have never seen operating derails on a model railroad, although a split-point derail could be made easily from a turnout.  It could even be power-operated.

Split-point derails are fairly uncommon on the prototype.  "Flop-over" derails are common.  Their small size would make them difficult to model.

Les

Les.

By "siding" are you referring to a track used for passing trains or a dead end track?  According to the rule book, a siding is a place for trains to meet and pass each other and a spur is a single connected track.  Just so we are on the same page as many modellers call "spurs" "sidings", which is the British term for a "spur". 

Of course not all spurs are built lower, sometimes it's physically not possible but I was talking generalities so generally speaking, spurs (That's a dead end track, in this case serving an industry) are lower than the main track.  For those that through physical needs have to climb away from the main or even a siding, then usually a derail is provided.

Sidings again are generally lower than the main track and usually not as well ballasted either but again, there are exceptions.

As for operating HO scale derails?  Google wan't much help, sadly.

[Trainman203]

50 years ago Model Engineering Works made an operating slide/over version of the flip over derail.  I had s couple on my layout.   Never saw very many split rail derails down here in Louisiana, all we ever saw were flip,overs.

[Piyer]

I have never seen operating derails on a model railroad, although a split-point derail could be made easily from a turnout.  It could even be power-operated.
Les

James McNab's Iowa Interstate features a lot of interesting goodies, including 1:1 scale-key-operated HO-scale switch locks, functional gates at the entrance to industries' property, and flip-over derails....

https://www.youtube.com/watch?v=Hfc5A3-iwuE

[Desertdweller]

Roger,

Sidings used as passing tracks generally will not have derails, unless they are also used for storing cars unattended.  The assumption is that trains in a passing situation will not be left unattended.  I know from experience that such is not always the case.  Flip-type derails are cheap and easy to install, and can prevent bad accidents.  They are marked by a nearby post or sign.

Flip-type derails are not always reliable.  They can break or be hopped over if hit hard enough.  They also are directional.  A car hitting one from the direction opposite from what it is supposed to be protecting can hop over the derail and stay on the track.  They are also cast, which makes them brittle and subject to breakage.  For situations where there is great danger of cars rolling out, split rail derails are used.  A split rail derail can be modeled by taking a regular track switch and removing one point rail, so only the point that lies against the stock rail (in the derailing position) remains.

One night, while running a Geep long-hood forward, I was mistakenly directed into a derail.  It was set in the derailing position, but oriented to derail cars coming out of the track I was going into.  The lead axel of my locomotive hopped over the derail and stopped.  Everything was still on the rails, the derail resting on the rail between the first and second axles of the truck.  We flipped the derail to the open position, and continued.

It is important to always check the position of the derail whenever opening a switch.

Les

[rogertra]

Roger,

Sidings used as passing tracks generally will not have derails, unless they are also used for storing cars unattended.  The assumption is that trains in a passing situation will not be left unattended.  I know from experience that such is not always the case.  Flip-type derails are cheap and easy to install, and can prevent bad accidents.  They are marked by a nearby post or sign.
[ Quote]

Yes, I know that.  I don't think that's what I wrote. 

I wrote about spurs having derails, not sidings.  Two different types of tracks though many modellers do use "siding" when they really mean "spur".  That's what adds to a lot of confusion, modellers incorrect use of railroad terminology.  If I discuss a siding to a railroader they know exactly what I mean but many modellers won't, they'll be thinking I'm talking about a spur.

In slow traffic times, sidings can be used for car storage as most sidings are below the track level on the main track so derails are not required.  The use of out of the way sidings keeps the yard tracks clear.  I used to do that on my old GER, use the siding at Dorset Centre to store cars during the "winter".

Yards are not for storing cars but for making and breaking up trains.  Another modelling "myth", "Yards are for storing cars".  No they are not.   

As for derails, I've used a derail many times, one with two padlocks actually.  One the museum's padlock and the other a CPR padlock.  Ditto for the switch stand and the gate giving entry to the museum's site.  Two padlocks on each until the CPR gave the museum permission to run down the spur, then the derail was moved to the CPR's side of the switch and the switch padlocked open for the museum. 

Fun and games.

Flip-type derails are not always reliable.  They can break or be hopped over if hit hard enough.  They also are directional.  A car hitting one from the direction opposite from what it is supposed to be protecting can hop over the derail and stay on the track.  They are also cast, which makes them brittle and subject to breakage.  For situations where there is great danger of cars rolling out, split rail derails are used.  A split rail derail can be modeled by taking a regular track switch and removing one point rail, so only the point that lies against the stock rail (in the derailing position) remains.

One night, while running a Geep long-hood forward, I was mistakenly directed into a derail.  It was set in the derailing position, but oriented to derail cars coming out of the track I was going into.  The lead axel of my locomotive hopped over the derail and stopped.  Everything was still on the rails, the derail resting on the rail between the first and second axles of the truck.  We flipped the derail to the open position, and continued.

It is important to always check the position of the derail whenever opening a switch.

Les

I've not seen a single point derail in Canada.  Not that they aren't used.  Of course, in the UK where every single switch either on or leading to a passenger carrying main track is interlocked, even on remote branch lines, all entry onto passenger carrying tracks is protected by some form of "trap".  Be it either a single or double point derail or a regular switch leading to a dead end "yard lead".

Cheers

Roger T.

[Trainman203]

There's two things being talked about here.  Neither is better than the other but they are worlds apart. They are 1) running a model railroad and 2) playing with trains.

[rogertra]

There's two things being talked about here.  Neither is better than the other but they are worlds apart. They are 1) running a model railroad and 2) playing with trains.

Agreed, 100%.

Cheers.

Roger T.