Midland Railway Block Bell Query

[sem34090]

Hello all!

 

I recently (Yesterday!) acquired a Midland Railway block bell (Of the integrated type with a tapper, similar to the GWR pattern) free-of-charge that I intend to get functioning for potential model railway use. It looks a bit like this one, but I've polished the bell up on mine:

My query is relating to the voltage and current required to power the thing, and also advice on connecting it to another machine (that will have to be built by yours truly!) for working a layout with. 

 

It does function as using three 'C'' type batteries (connected in parallel, I think though they might be in series) from my Bardic Lamp I was able to get the striker to 'twitch' slightly.

 

sem34090

[The Stationmaster]

I have run GWR pattern block bells on 12v dc in the past with no apparent problems although a lower voltage might well be sufficient.  (Similarly I've used 12v dc on GWR block instrument and even with the coil energised for a while there were no problems.)

[timbowilts]

On the old Western Region in Cornwall we used 12v for block lines.

Tim T

[RailWest]

I have used 12V in the past on SR equipment for model railway purposes, but in hindsight would not recommend it - the 'hammer' does live up to its name when it hits the dome, whilst needle indicators do their best to knock out the limiting pin! Don't forget that prototype equipment has to work over much greater distances than just one end of a model to the other, so suffer from voltage drop over the line.

 

I would suggest you try 6V first - if it works OK, then no need for anything stronger IMHO.

[sem34090]

So perhaps about 9v would be a good medium? I will try 6v first though.

[TheSignalEngineer]

Voltage applied to Block and Bell circuits in the real world are highly dependent on the length of the circuit and the weight of copper wire used. As Railwest says 12v is far too much for indicators, the Spagnoletti type used are designed to work on about 3 cells although those used for signals did come with different coil resistances for different circumstances.

For block bells I have seen instances on long sections with poor line wires using 12 or more cells to get a reliable ring. On short sections with 200lb copper open wire and earth return they would work quite happily on 9 cells or less.

[kevinlms]

Hello all!

 

I recently (Yesterday!) acquired a Midland Railway block bell (Of the integrated type with a tapper, similar to the GWR pattern) free-of-charge that I intend to get functioning for potential model railway use. It looks a bit like this one, but I've polished the bell up on mine:

My query is relating to the voltage and current required to power the thing, and also advice on connecting it to another machine (that will have to be built by yours truly!) for working a layout with. 

 

It does function as using three 'C'' type batteries (connected in parallel, I think though they might be in series) from my Bardic Lamp I was able to get the striker to 'twitch' slightly.

 

sem34090

Whether or not you get it to work satisfactory (I'm sure you will), its an excellent find and at a good price!

[sem34090]

One can never argue with a price of £0.00!

 

It came from Medstead and Four Marks - It and an old GPO telephone had been donated to the station but we had no use for either of them. On Thursday I was on duty and the stationmaster said they were probably going to look for someone to take them off our hands. I simply asked "Could I take them off your hands?" he said "I can't see why not", I asked "How much do you want for them and can I take them tonight?" and he responded "No price, though a donation would be good, and you can certainly take them tonight!".

[uax6]

You can always adjust to ring on the bell by adding in line resistances. If its beating the bell too hard, add resistors to the line wire which will simulate the miles of open wire in the real thing, and then try again.

 

For example the GPO based all their telephone circuits on having a 1000 ohm line wires, the 706 tele having a circuit board inside that could be reversed for long and short lines....

 

Andy G

 

(btw was in an antique shop yesterday and there was a Midland pattern block instrument in tatty condition for £260, and a couple of generic oil hand lamps for £60.....)

Edited December 30, 2018 by uax6

[sem34090]

Ouch... I'd only even consider £60 for a handlamp if it was in good condition and had a burner inside.

[LNERGE]

10 to 12 volts is about right. I've just set up some lineside circuits a few miles in length. I started by putting 12v to line then going to the far end and seeing what actually arrived at the other end. The power source was stepped up to give something like the original value at the far end and all works nicely. The key token circuit has a 50v supply That comes from a QXR1. The QXR1 is a very small transformer/rectifier unit that does put out 50v but hasn't got a lot of go in it and seems ideal for the Eastern Region key token circuit.