neale126

Finally managed to get the Walkers instruments working and talking to each other. As I mentioned previously they had been modified for 2 wire plus return operation and also for use split supplies. They proved to be fiddly to operate and get unambiguous operation and the order sequence in which everything was actioned had to be right. It quickly became very clear that they were not suitable for use on the actual railway so they have now been consigned to the railway museum. Many thanks for all who provided information and advice. Regards, Neale.

Firstly, thanks for all your help and information. The sets I have were probably a later iteration where a electro-mechanical commutator lock was added but all the diagrams and sketches I have accrued to date are for the previous version without the lock function. I have now fathomed out what the wiring modifications were and the reasoning behind them. The idea was, apparently, to make them work for single line operation and to run them from a split supply. The extra resistor and diode provide protection so the lock solenoid only operated with a +ve voltage and the resistor gave current protection. The modified sets were to use 2 wire and return between signal boxes. For the moment I have put the units to one side until I can get more connectors to complete the inter unit wiring. Neale.

I stand corrected. I thought they might have been lead acid but historically that has to be wrong.

Phil, those are just what I wanted. Thank you. I also have the matching connector leads that mate with the modified wiring etc., so with a bit of luck I can see how they were going to be used in the modified state. Chris, I agree so will be recehecking everything just to make sure before powering up. In the first instance I will be using current limited bench power supplies and starting with maybe 6 volts. I would imagine that the line resistance would be the main reason for having higher voltages. The diagram show 7 cells which is nearer 14 volts. Neale.

OK I have attached a corrected circuit diagram with the back contact on the Bell Push. Also the wire colour positions have been moved as they are not original and at this point not relevant. Michael, thank you for your comments and suggested procedure. The diode and the resistor were added around 2010 as was the wiring. I doubt the diode is to suppress BEMF and has been added to allow only the correct polarity signal to release the commutator lock. The commutator is definitely only 2 position. When turned to the right (L1 activated) the disc shows clear in the port hole. When turned to the left the TRAIN IN SECTION disc is dragged into the window in front of the BLOCKED disc and the associated tail appears below the box. Physical moving the tail can make the TRAIN IN SECTION disc disappear to show BLOCKED. Moving back to CLEAR) resets TRAIN IN SECTION disc so it is in front of the BLOCKED disc. Hope that makes sense. I am quite happy to ignore the added wiring and connect the two systems up as they would have originally be designed. The problem I have is that I don't know for certain what that is at the moment. Again thanks for all your help. Neale.

Chris, The spring arms are isolated and, apart from the missing NC contact, are as the diagram. The block behind the striker on the top spring arm is an insulator. I'm not much of photographer but have included another couple of photos. Nick, thanks for the links. Unfortunately all the instrumentation in the PDF seem to be the later 3 wire type. The LNER document is interesting but uses a galvanometer indicator and requires tokens. Neale.

Chris, You are correct in that the terminal ringed in orange is a back contact (N.C.) that connects to SW1 pin 3 in the diagram which in turn goes to the white wire and the diode. As nothing was actually connected to it I missed that. The wire in the second image, circled in orange, is the link via the back panel to SW2 pin 3 on the commutator. It is buried in a slot and filled in and is original. The main problem I have is that the person who added the modern wiring, extra components and connectors did this several years ago and died soon after. Unfortunately nothing was documented. This is why I am hoping that someone may either have circuit diagrams or a system interconnection diagram. Many thanks. Neale.

Chris, The contacts are both NO and close when the button is pushed. The commutation is not mechanically biased and cannot be turned to Clear ubless the Lock Coil L1 is activated. Neale.

I have drawn out the circuits and added pictures of the internals. The relays and solenoids do all seem to work when individually powered with a low voltage. In the Control Box I am not sure whether the Diode D1 or the Resistor R1 are original fit and have been added when the additional wiring was carried out. In the Bell and Block Indicator box the white signal indicator is released (drops) when the upper solenoids are activated. A pin holds the signal until the solenoid is driven. Similarly the Bell Solenoid has to be activated to release the red signal and a pin on the actuating arm also holds this in position. What I don't know is exactly how these two boxes are connected together and to the outside world. Neale.

Firstly thanks to all for their replies. Chris. There is no internal marking on the connections unfortunately. That would be too easy. Someone has already added connectors to both units, three pins on the Block Indicator/Bell and 6 pin connector on the Control Box. I think that probably 3 wires from the Block Indicator go to three pins on the Control Box with the remaining three pins from that to the outside world. I have assumed (hopefully correctly) that those three wires are the signal line, +V supply and earth. The information from the BR(S) Supplement is useful so thank you. I will post pictures from inside the boxes and I am also going to sketch out the circuit so I can attempt to follow the sequences. This I will also post. Michael, I will post on 'The Signal Box'. Thanks for the suggestion. There are two sets of boxes so I have enough for both ends of a block. I am reluctant to place any power on the units until I have some idea what the original design voltage was. later instruments probably used 12 volt but due to the age of these it may be lower. Neale.

I have a couple of Victorian Block instrument sets which I was hoping to install between the two signal boxes on a private 2' gauge railway to supplement the telephone system currently used. I have identified the boxes as a Walkers 1 wire 2 position Block Instrument with top mounted bell and a Walkers 1 wire Block Instrument Control Box incorporating bell key and disc indicator. Not model railways but I would be grateful for any information/references concerning operation or technical details about them. Each instrument consists two parts; the indicator/bell unit and the control unit. There are three wires between the indicator/bell and the control boxes and then three wires from the control box to the outside world. My problem is that I cannot find any additional information these such as how they were operated and connected into a system. They are well made, if slightly over the top compared to later units, and appear to be in working order. I guess they were manufactured in the late 1800's. Can anyone can provide information or links please? Thank you. Neale.

As Martin said we had quite a few problems with Tortoise motor wipers on a large exhibition layout. The motors were more than 10 years old and despite regular cleaning some still gave problems, which at an exhibition, was far from ideal. After applying Electrolube SGB 2X contact grease the problems disappeared. Apply sparingly. It is available from Farnell RS and Rapid plus others. Neale.