How do train buzzers work?

[E_Reeves]

Having been on a cab ride on a DMU on the Battlefield Line at Bosworth, I got to press the buzzer (2 buzzes) to tell the driver to go. I was wondering what system it uses, as I can't find any information anywhere on the internet.

 

[scott118]

http://www.railforums.co.uk/showthread.php?t=12091

 

[E_Reeves]

http://www.railforums.co.uk/showthread.php?t=12091

I mean like the actual hardware that they use.

 

[Jonny]

I mean like the actual hardware that they use.

Do you mean the sound of the buzzer?

 

[E_Reeves]

Do you mean the sound of the buzzer?

Yes, and the panel the buzzer button is on.

 

[8J]

I guess it uses the 110v supply found on most DMU's and is interlocked and operated by the train wire system. Rather complicated! Someone else hopefully should be able to expand on that.

 

[Phil.]

The question was concerning a DMU on the battlefield line. This is a private line run by enthusiasts and operating - amongst other things - a first generation DMU. There was no interlocking with the buzzer signal on these nor was the insertion of a key required to enable the buzzer to work.
Pushing any one of the buzzer operating buttons closed a simple electrical circuit energising the buzzer.

 

[HarleyDavidson]

A bit like a doorbell without the bell, the hammer just hits a metal strip or such like, modern stock it's an electronic bleeper.

 

[QueensCurve]

1: Stop 2: Ready to Start 3: Set ...yowncabin.com/electrical/doorbell-wiring.html

 

[Jonfun]

The question was concerning a DMU on the battlefield line. This is a private line run by enthusiasts and operating - amongst other things - a first generation DMU. There was no interlocking with the buzzer signal on these nor was the insertion of a key required to enable the buzzer to work.
Pushing any one of the buzzer operating buttons closed a simple electrical circuit energising the buzzer.

I thought the key needed to be in the desk for most (all?) first gen DMUs buzzer to be operative?

 

[Phil.]

I thought the key needed to be in the desk for most (all?) first gen DMUs buzzer to be operative?

I was referring to the Guard's operation.
--- old post above --- --- new post below ---

In aviation there is also:-

8: Someone is having sex in the toilet.

I heard that on a recent flight from Heathrow to Vancouver.
--- old post above --- --- new post below ---


I think it is just a simple bellwire.

http://www.buildmyowncabin.com/electrical/doorbell-wiring.html

4 should read, "slow down whilst propelling".
Propelling is defined as the train being driven from any cab other than the leading one.

 

[Jonfun]

I was referring to the Guard's operation.

The key still needs to be in a desk for any of the buzzers to work, Guards' or Drivers'.

 

[davetheguard]

The key still needs to be in a desk for any of the buzzers to work, Guards' or Drivers'.

And I think the "bell" (not Buzzer on these sets) used on the now-withdrawn Hampshire DEMU's on the old Southern Region of B.R. required the Guard's B.R.1 key to be inserted & turned in the Brake compartment to work.

 

[Phil.]

JonFun. Yes the Driver needs to have inserted his key but no key is required for operation by the Guard.

DavetheGuard. Yes, this was true of all Southern Region slam-door multiple unit stock and indeed the 508/455 family. The Guard had to insert the 21 key in for operation.

 

[Taunton]

1 : stop, and 2 : Ready to start, also used to be given by guard to driver approaching a request stop, to indicate whether there were passengers to alight or not. Driver gave a 1 back to guard if they could see there were passengers waiting. I've not been through a request stop for a long time so don't know if this is still done.

Never heard a 6 for draw forward, despite a couple of times being in a 4-car at Woking which during disruption had drawn up mid-platform as normal, and then got a PA traincrew announcement to draw up to the 12-car mark for an unscheduled attachment behind. That was just done with a 2.

 

[craigybagel]

1 : stop, and 2 : Ready to start, also used to be given by guard to driver approaching a request stop, to indicate whether there were passengers to alight or not. Driver gave a 1 back to guard if they could see there were passengers waiting. I've not been through a request stop for a long time so don't know if this is still done.

Never heard a 6 for draw forward, despite a couple of times being in a 4-car at Woking which during disruption had drawn up mid-platform as normal, and then got a PA traincrew announcement to draw up to the 12-car mark for an unscheduled attachment behind. That was just done with a 2.

Request stop buzzers seem to vary between company, or even between depot! 6 is still used on occasion. I've used it myself (with prior agreement with the driver) at 2 separate locations where there is a signal visible from the platform but not close enough to be considered a starting signal, and where the signal won't come off until the train has left the platform. It's technically not required, but its an extra safety net. I've used it when we've been asked to move a unit within the platform as well.

 

[swt_passenger]

C'mon chaps, the question was about how the buzzers WORK, not how are they used. A majority of replies are about what the codes mean, as though no one ever read the third post, clarifying what the OP wanted...

 

[headshot119]

Having been on a cab ride on a DMU on the Battlefield Line at Bosworth, I got to press the buzzer (2 buzzes) to tell the driver to go. I was wondering what system it uses, as I can't find any information anywhere on the internet.

The buzzers themselves are just a simple electromechanical setup. Applying a voltage (24v) across them causes the armature to vibrate and to create the buzzing sound you hear.

I'll have a look and see if I can find you a photo of the inside of one, knowing my luck I'll only have a picture with the cover on.

The only photo I can find in my collection is the one in the cab of 121032 when it visited Llangollen three years ago. You can see the buzzer in the top of the photo, along with the TPWS panel and the Air & Axle panel.

121032 Cab by Karl [Headshot119], on Flickr

This next photo shows the driving desk, the buzzer is the small push switch next to the key lock.

121032 Cab by Karl [Headshot119], on Flickr

As for how the circuit works (As mentioned below there are probably exceptions to this rule):

The Driver must have inserted his FG1 key (Different to the key used in more modern units) into a desk somewhere in the formation, this is usually in the leading cab.

This will energise wires 33 and 34. Very important, without these two wires being energised the buzzers won't work, either in the cab, or in the guards van.

When either the driver or guard presses the buzzer button; which is a simple push to make button, you connect wire 33 and 34 together through the buzzers. Meaning they will sound right down the train.

The buzzers will also sound if a handbrake (Fitted with a switch) is on, this connects wire 42 and 34 together through the buzzers, and cause the buzzers to sound constantly until the offending handbrake is taken off.

If you need any further information just let me know.

JonFun. Yes the Driver needs to have inserted his key but no key is required for operation by the Guard.

DavetheGuard. Yes, this was true of all Southern Region slam-door multiple unit stock and indeed the 508/455 family. The Guard had to insert the 21 key in for operation.

As the OP is referring to the Battlefield line, so it's a first generation DMU he's asking about.

Most if not all (The lovely thing about the first generation units is the exceptions to the rules) require an FG1 key to be in a drivers desk somewhere in the formation before the buzzer will work anywhere on the formation.

A good hint the driver isn't ready!