Facing Point Locking Bars

Discuss the prototype and how to model it.
Armchair Modeller
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Facing Point Locking Bars

Postby Armchair Modeller » Sat Jun 30, 2018 9:51 am

I have to make 2 new locking bars for Ulpha as part of the track replacement programme. Just wondering, first of all, if there are kits available covering all the detail. I had a good look on the Internet, but nothing came up.

Looking at drawings of locking bars in Raynar Wilson's 'Mechanical Railway Signalling' there is quite a lot of detail in the real thing, including the clips, brackets and arms that hold the bar to the rail etc.

Also, am I right in assuming that the preferred location for a locking bar is inside the rail, operated by the wheel flanges and the bars outside the rail, operated by the wheel tread, would only be used where an inside bar was impractical?

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grovenor-2685
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Re: Facing Point Locking Bars

Postby grovenor-2685 » Sat Jun 30, 2018 11:31 am

Also, am I right in assuming that the preferred location for a locking bar is inside the rail, operated by the wheel flanges and the bars outside the rail, operated by the wheel tread, would only be used where an inside bar was impractical?

Yes.

Mind you, my personal view is that locking bars at a light railway location such as Ulpha are unlikely as the location of the signals with respect to the facing points means that the locking bars don't really have a route holding function and the risk of anyone trying to work the points under a train is minimal considering that they are right under the nose of the lever frame operator and the speeds at the point locations is very low.

For components, there may be something in the Ambis range.
Regards

Armchair Modeller
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Re: Facing Point Locking Bars

Postby Armchair Modeller » Sat Jun 30, 2018 12:51 pm

Thanks Keith. That answers my next question too - i.e. whether they are actually required or not. Sounds like best advice would be to forget about them altogether. :thumb

Terry Bendall
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Re: Facing Point Locking Bars

Postby Terry Bendall » Sat Jun 30, 2018 4:57 pm

The Leighton Buzzard Narrow Gauge Railway in Bedfordshire (2 foot gauge) has facing point locks on a crossover which carries loaded passenger trains. The actual locking mechanism is outside the running lines with an extended stretcher bar.

Terry Bendall

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grovenor-2685
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Re: Facing Point Locking Bars

Postby grovenor-2685 » Sat Jun 30, 2018 4:59 pm

But does it have facing point lock bars? The locks are not in question.
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Phil O
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Re: Facing Point Locking Bars

Postby Phil O » Mon Jul 02, 2018 12:54 pm

grovenor-2685 wrote:
Also, am I right in assuming that the preferred location for a locking bar is inside the rail, operated by the wheel flanges and the bars outside the rail, operated by the wheel tread, would only be used where an inside bar was impractical?

Yes.

Mind you, my personal view is that locking bars at a light railway location such as Ulpha are unlikely as the location of the signals with respect to the facing points means that the locking bars don't really have a route holding function and the risk of anyone trying to work the points under a train is minimal considering that they are right under the nose of the lever frame operator and the speeds at the point locations is very low.

For components, there may be something in the Ambis range.
Regards


But not unheard of Keith, back in the eighties the fireman climbed down off the engine as passed the ground frame, he inserted the Annets key released the lock and reversed the turnout, between the bogies of coach S1000, the coach continued down both roads until the trailing bogies could no longer resist the forces exerted on it and derailed. Nobody was injured and just as the track gang were preparing to go home there was a quick about face, light a fire in the warmest boiler and marshal a recovery train and see what damage needed to be sorted.

S1000 is a prototype fibreglass bodied coach and has been involved in several incidents during it's life. The worst of which happened somewhere on the eastern section of the Southern, but I can't remember where. It's also a survivor as it's still in use on the East Somerset Railway.

Phil.

John Palmer
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Re: Facing Point Locking Bars

Postby John Palmer » Mon Jul 02, 2018 1:57 pm

Phil O wrote:...he inserted the Annets key released the lock and reversed the turnout, between the bogies of coach S1000...

That must have involved some fairly precise positioning over a bar less than the 'standard' 40' length!

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grovenor-2685
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Re: Facing Point Locking Bars

Postby grovenor-2685 » Mon Jul 02, 2018 3:58 pm

Its not usual to have lock bars on ground frames, for the very reason that the operator can clearly see what is happening, and movements are slow et.
Of course such things happen, but rarely.
If anyone wants to research the provision of facing point lock bars at similar light railway terminals, feel free, the answer may be interesting.
For now my view is that lock bars would be unlikely in such a case. That does not mean that they were never provided. :)
Regards

Armchair Modeller
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Re: Facing Point Locking Bars

Postby Armchair Modeller » Mon Jul 02, 2018 4:42 pm

Unlikely suits me Keith.

The only reason the question occurred to me is that one appears to have been modelled on the original trackwork I am replacing on Ulpha. Otherwise, the question would never even have occurred to me.

Thanks again for everyone's advice. :thumb

Phil O
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Re: Facing Point Locking Bars

Postby Phil O » Mon Jul 02, 2018 6:08 pm

John Palmer wrote:
Phil O wrote:...he inserted the Annets key released the lock and reversed the turnout, between the bogies of coach S1000...

That must have involved some fairly precise positioning over a bar less than the 'standard' 40' length!


No locking bar, the system relies on the token remaining on the loco until it's run round and got to the turnout to get from the loop back on to the main. The Annets key unlocks the facing point lock lever, when this is reversed it allows the turnout to be reversed. The loco proceeds on to the main all is reset and locked, the fireman then rejoins the loco and shows the driver the token, the loco then sets back on to the train.

In this instance, the rules were not obeyed and the fireman alighted from the train as it ran into the platform and for some reason rather than wait until the train had passed over the facing turnout and stopped safely and then unlocked the point lock, he for some reason did what he did and caused an incident. He lost his passed fireman status and was put back for a number of years, but resigned shortly afterwards.

The public took it all in good stead and a number and most actually enjoyed it.

Phil


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