Westinghouse brake controllers

[darwins]

Hello

Can anyone tell me the model of Westinghouse brake controller that was fitted on London Underground trains before they were fitted with EP brakes?

Also was the same model of brake controller fitted to the Metropolitan and District locomotives and/or did they have any independent locomotive brake?

[bruce]

I believe it was a Westinghouse Number 4 Brake valve as fitted to Metropolitan locomotive L12 Sarah Siddons.

[metman]

I’m no expert but I believe there were variations in equipment. The F stock of 1920 were refitted with Westinghouse type 21 (or A type) brake controllers which also incorporated an Electro Pneumatic (EP). These were replaced with ex standard stock brake controllers in 1950.

The P stock had the ‘A’ type brake controller modified for regenerative braking with the Metadyne equipment.

The R stock (R38) cars were actually fitted with brake controllers destined for refurbished T stock.

I hope that helps although there is much more information out there than what I can offer.

[DWS]

Nov 6, 2020 19:31:25 GMT bruce said:

I believe it was a Westinghouse Number 4 Brake valve as fitted to Metropolitan locomotive L12 Sarah Siddons.

Metropolitan locomotives never had a L prefix.

[darwins]

Nov 6, 2020 21:56:27 GMT metman said:

I’m no expert but I believe there were variations in equipment. The F stock of 1920 were refitted with Westinghouse type 21 (or A type) brake controllers which also incorporated an Electro Pneumatic (EP). These were replaced with ex standard stock brake controllers in 1950.

The P stock had the ‘A’ type brake controller modified for regenerative braking with the Metadyne equipment.

The R stock (R38) cars were actually fitted with brake controllers destined for refurbished T stock.

I hope that helps although there is much more information out there than what I can offer.

Thanks.  The type A was the first EP controller.  I didn't realise that the Metadyne units controller was modified from a regular Type A - it had a few extra positions.  The description given in Agnew being:

1 Release or Running

2 Holding

3 Regeneration 1

4 Regeneration 2 and EP

5 Regeneration 3 and EP (identical to notch 4 in practice)

6 Lap Air

7 Service Air

8 Emergency

I am hoping to find which controller was used before that.

[metman]

Check out early district trains articles in Underground News by Piers Connor that night we’ll have the information you need.

[class411]

Nov 7, 2020 8:39:27 GMT darwins said:

Nov 6, 2020 21:56:27 GMT metman said:

I’m no expert but I believe there were variations in equipment. The F stock of 1920 were refitted with Westinghouse type 21 (or A type) brake controllers which also incorporated an Electro Pneumatic (EP). These were replaced with ex standard stock brake controllers in 1950.

The P stock had the ‘A’ type brake controller modified for regenerative braking with the Metadyne equipment.

The R stock (R38) cars were actually fitted with brake controllers destined for refurbished T stock.

I hope that helps although there is much more information out there than what I can offer.

Thanks.  The type A was the first EP controller.  I didn't realise that the Metadyne units controller was modified from a regular Type A - it had a few extra positions.  The description given in Agnew being:

1 Release or Running

2 Holding

3 Regeneration 1

4 Regeneration 2 and EP

5 Regeneration 3 and EP (identical to notch 4 in practice)

6 Lap Air

7 Service Air

8 Emergency

I am hoping to find which controller was used before that.

It's fairly clear what 1,2, and 8 mean, but it would be fascinating to know the details of the other positions.

[darwins]

Nov 7, 2020 9:40:27 GMT class411 said:

Nov 7, 2020 8:39:27 GMT darwins said:

It's fairly clear what 1,2, and 8 mean, but it would be fascinating to know the details of the other positions.

I shall try and explain - this will be a long post.

Firstly, you may be aware of two features of the original Westinghouse air brakes that make them different to modern brakes.

(1) They were not self-lapping - so when you put them in APPLY the brake pipe pressure will continue to decrease until either it reaches the minimum service value or you move the handle to LAP.

(2) They did not have graduated release - that is to say once applied you could make a stronger application (by moving from lap to apply and back again) but you could not reduce the strength of the brake application - to make a more gentle application you moved the handle back to RUNNING / RELEASE and waited for the brakes to release fully before applying them again.

So the positions on the Westinghouse air brake controllers used in the early 20th century were:

RELEASE - released the brakes quickly by connecting the brake pipe directly to the main air reservoir - if left in this position the brake pipe pressure could rise above the normal working pressure

RUNNING - maintained the normal working pressure in the brake pipe via a feed valve and equalizing reservoir - released the brakes more slowly

LAP - used to hold a particular brake pipe pressure less than normal = used to hold chosen strength of brake application (pressure might drop slowly due to leakage though)

APPLY - let air out of brake pipe slowly until minimum service pressure was reached = slowly increasing strength of brake application up to maximum.

EMERGENCY - rapidly let air out of brake pipe - leading to full brake application in minimum time.

The first type of EP brake used on the underground (Type A) used on F stock and I were similar as they were not self-lapping and did not have graduated release for either the EP brake or the air brake.  It was intended that the EP brake controlled by electrical signals would be used as the normal brake with the air brake for back up in case of failure.  The positions on the controller were:

RELEASE/RUNNING - released the brakes using electrical signal and also charged or returned the brake pipe pressure to normal if air brake had been used.

EP HOLD - holds an application of the EP brake at the same strength

EP APPLY - applies brakes slowly using an electrical signal (but air train pipe pressure is not reduced)

LAP AIR - holds an air brake application (as above)

APPLY AIR - applies brakes slowly by reducing pressure in air train pipe

EMERGENCY - rapidly let air out of brake pipe - leading to full brake application in minimum time.

So that leads to the one you asked about at last.  This is my attempt to describe braking on the Metadyne stock:

1 Release or Running - released the brakes using electrical signal and also charged or returned the brake pipe pressure to normal if air brake had been used.

2 Holding - holds an application of the regenerative brake and the EP brake at the same strength

3 Regeneration 1 - only the regenerative brake is used (motors are used in reverse as generators to feed power back into the live rail)

4 Regeneration 2 and EP - the ordinary air brakes are slowly applied by an electrical signal in addition to the regenerative brake being used

5 Regeneration 3 and EP (identical to notch 4 in practice - possibly there was some intention for this to give a faster application than 4)

6 Lap Air - holds an air brake application with reduced pressure in brake pipe

7 Service Air - applies ordinary air brake by reducing pressure in brake pipe gradually

8 Emergency - rapidly let air out of brake pipe - leading to full brake application in minimum time.

Later versions of EP brakes such as the Type D used on the 1938 stock had self-lapping EP brakes with graduated release (although the air brake back up remained non-self lapping and without graduated release).  This means that a bit like the brake pedal on a car you can increase or decrease the brake strength as you wish. The positions on the Type D brake controller were

I RUNNING / RELEASE

II >>>>>>>>>> EP SERVICE >>>>>>>>>> III - brake application more or less depending on position

III LAP AIR

IV APPLY AIR

V EMERGENCY

There is an excellent description of this type of EP brake in this BR video

[class411]

Thank you so much for taking the time and trouble to explain that so comprehensively and clearly.

I think I have learned a lot from that.

The most surprising thing being that there was regenerative braking in trains so early - I had no idea. I suppose it was much easier when there were no electronic controllers between the power source and the motors.

[norbitonflyer]

Nov 8, 2020 9:36:51 GMT class411 said:

The most surprising thing being that there was regenerative braking in trains so early - I had no idea.

Even earlier than I realised - Frank Sprague was using it in electric streetcars 50 years before the Metadyne.

Following an accident in 1911 attributed to a failure of a regenerative brake, the technology was banned in the UK for some years
tramwayinfo.com/tramways/Download/Raworth.pdf

(Date was 11pm on 11/11/11,and one the trams involved was No 11)

[countryman]

Nov 8, 2020 9:36:51 GMT class411 said:

Thank you so much for taking the time and trouble to explain that so comprehensively and clearly.

I think I have learned a lot from that.

The most surprising thing being that there was regenerative braking in trains so early - I had no idea. I suppose it was much easier when there were no electronic controllers between the power source and the motors.

I assume that this is because, with DC, there is no need to synchronise the frequency. I assume this has to be done with any feed into the national grid, whether from DC soolar panels or AC (presumably) wind generators.

[zbang]

When feeding energy back into "the grid", yes, it must be sync'd, however this is possible with modern power electronics which can track both the frequency and the flows in/out; a type of engineering that I presently consider some sort of Dark Magic. (Solar/wind power feeds are much easier than transit/etc supplies as their flow is one-way- see "grid-tie inverter".)

IIRC one of the main early problems with regen braking is that unless there were enough loads to soak up that energy and the converter regulators fast enough, the DC bus voltage could rise excessively (again, more modern controllers limit this).


BTW (from memory), the Norfolk & Western RR (West Virginia, USA) did regen braking probably 90 years ago into their AC system (25Hz 11KV), but the motors were synchronous so it wasn't such a problem.

[roythebus]

I'd suggest you look at the Isle of Wight steam railway for the original Westinghouse brakes used in the UK as they are one of the few steam railways that use the Westinghouse brake for all their trains.

The brake handle positions are:

Release, running & charging

Lap

Application

Emergency.

Another type has:

Quick release, this gives an overcharge for a quick release

Running and charging

Lap

Application

Emergency.

I'm used to the first type, having driven the Southern Region 4SUB and Waterloo & City trains that were only fitted with Westinghouse brakes.

Somewhere around I've got the LT hand-outs on the Westinghouse brakes that were issued at White City in the 1960s and 70s.

Indeed it was possible to run out of air using the Westinghouse brake. Each coach has an auxiliary air reservoir which has enough capacity for 3 applications. Air flow to the brake cylinders was via a triple valve, a rather complex bit of kit which I won't try to explain here!

I thought the Met electric locos were fitted with a Gresham & Craven vacuum brake for loco-hauled stock and a Westinghouse air brake mainly for the loco. The operation of either brake handle would cause the other brake to operate as well. The Brighton Terriers on the K&ESR have a Westinghouse brake on the loco which in turn operates a vacuum brake on the train!

I think Sarah Siddons has been fitted with a more modern air brake handle as spares are easier to obtain!

[zbang]

Nov 11, 2020 18:32:53 GMT roythebus said:

Indeed it was possible to run out of air using the Westinghouse brake. Each coach has an auxiliary air reservoir which has enough capacity for 3 applications. Air flow to the brake cylinders was via a triple valve, a rather complex bit of kit which I won't try to explain here!

The single brake pipe reservoir-exhaustion problem led to both the multi-pipe systems and to electrically-controlled triple-valves (of which, IIRC, there are several competing systems). Single-pipe also has the difficulty on longer trains that brake application (and recharge) depends on the speed of air movement in the single pipe; a US-length goods train could take over 20 minutes to charge the entire system from empty.

For the curious, there's a decent write-up* at trn.trains.com/bonus/wabtec

*with some very bad letterspacing, sigh

[rincew1nd]

Nov 11, 2020 18:32:53 GMT roythebus said:

I'd suggest you look at the Isle of Wight steam railway for the original Westinghouse brakes used in the UK as they are one of the few steam railways that use the Westinghouse brake for all their trains.

The brake handle positions are:

Release, running & charging

Lap

Application

Emergency.

The Talyllyn also uses the Single-pipe Westinghouse system, when initially fitted in the 90s many parts were obtained as surplus to LUL.

[darwins]

Nov 11, 2020 18:32:53 GMT roythebus said:

I'd suggest you look at the Isle of Wight steam railway for the original Westinghouse brakes used in the UK as they are one of the few steam railways that use the Westinghouse brake for all their trains.

The brake handle positions are:

Release, running & charging

Lap

Application

Emergency.

Another type has:

Quick release, this gives an overcharge for a quick release

Running and charging

Lap

Application

Emergency.

I'm used to the first type, having driven the Southern Region 4SUB and Waterloo & City trains that were only fitted with Westinghouse brakes.

Somewhere around I've got the LT hand-outs on the Westinghouse brakes that were issued at White City in the 1960s and 70s.

Indeed it was possible to run out of air using the Westinghouse brake. Each coach has an auxiliary air reservoir which has enough capacity for 3 applications. Air flow to the brake cylinders was via a triple valve, a rather complex bit of kit which I won't try to explain here!

I thought the Met electric locos were fitted with a Gresham & Craven vacuum brake for loco-hauled stock and a Westinghouse air brake mainly for the loco. The operation of either brake handle would cause the other brake to operate as well. The Brighton Terriers on the K&ESR have a Westinghouse brake on the loco which in turn operates a vacuum brake on the train!

I think Sarah Siddons has been fitted with a more modern air brake handle as spares are easier to obtain!

Thanks for that.

I would very much like to see your hand outs. If ever you find them I hope you will be able to upload a copy.

The Met electric locos are another matter - whilst they were mostly intended to haul vacuum braked stock, the Westinghouse brake was a regular train brake - the two pipes at the front of the locos were one for vacuum and one for air - It would be interesting to find out more about the idea of each brake working the other.  I can follow that the vacuum train brake could operate the air brakes on the loco - but not so sure about doing the same in reverse.

The new air brake system on Sarah Siddons is a BR twin pipe system.

I presume the LT and SR Westinghouse Brakes worked with 90 psi in the main reservoir and 70 psi for the train pipe.

[fish7373]

Hi back before the brakeing system was changed if i remember Sarah Siddons had two brake cylinders one for VACUUM AND ONE FOR AIR she had a No 4 brke handle for air and one for Vac Brakes that`s the old Sarah today the brakes are out of a class 33 loco which is D&M Brakeing system with one brake handle which work both brakeing systems AIR & VAC through a proportional valve The loco had its VAC Cylinders removed and just has Air Cylinders and has a straight air brake handle to work the air brakes only The right position for No 4/ No/ 6 is 1 charging train and releasing the brakes 2 whislst running 3 lap 3 to 4 applying thge brake 5 emergency 12345 are the position of the brake handle that`s out of a LT air brke instruction book have a lot info but long winded putting on here because of photobucket Thanks if right.

[roythebus]

LT worked on 90psi main res with 65 psi on the brake pipe (to use BR terminology).

BR worked on 90psi-120psi main res with 70 psi on air-braked stock with 65 psi on Westinghouse only EMU stock such as the 4SUB.

In the latter part of the 1970s, maybe 1978 BR upped the brake pipe pressure to 5bar/72.5 psi to make it standard to the common European pressure. This meant BR and European freight stock ould work together. there was a change-over period of about 3 months where we sometimes had to go along a train and pull the brake release strings on the stock if we had an unconverted loco going onto a train that had been charged to 5 bar! It would not be possible to blow the brakes off.

Modified BR locos had a yellow spot on the brake handle so the driver could identify that it had been modified.

Some of the "redundant" BR brake equipment also found its way to an off-shore location in somebody's drivers bag so I've heard.

Proportional valves were available that word work both systems air/vac and vac/air.

[darwins]

Since we have delved into early EP brakes here (as well as Westinghouse), I have some further questions.

For the original Westinghouse brakes I believe the triple valves did not have graduated release. So once the pressure in the train pipe begins to rise the triple valve goes into release position and you lose all the air from the brake cylinders.

Now thinking about the driver's brake valve RELEASE / LAP / APPLY - you can hold an application with the lap position, increase the application some more, hold it again. But what happens in release? I assume that you would have to keep the handle in the Release (or Overcharge or Running) position until the full 65 or 70 psi was restored in the brake pipe. Was there anything in the controller to stop you lapping the brake before the pressure was fully restored to the train pipe? I can imagine that with the above system if you lapped with less than the full pressure in the brake pipe that might reduce the strength of any further reapplications.


For EP brakes am I correct to assume that the for the air brake part of the type A and type D controllers this worked exactly as the early Westinghouse brake and did not allow partial release?

For the Type D controller between I and II it was possible to vary up or down or hold any pressure in the brake cylinders. For the type A controller was it possible to reduce the pressure in the brake cylinders by moving from EP Hold to Release and back again?