vac, steam, air pipe fittings colours

[buffalo]

Can someone please enlighten me about the colour coding used on vacuum, steam and air pipe fittings in the mid-1960s? I'm adding some details to a Heljan Hymek (4mm) and am getting very confused I've been looking at photos, mostly of preserved engines which appear to show at least two different schemes. Was the coding fixed or did it change over time? Two examples, both showing D7017 at different times, have red fittings on the vac pipe but on this one the air pipes appear to be white with yellow on the steam pipe, whereas on this page the reverse seems to be true.

 

Nick

[45125]

Hi

 

The vac pipe is usually red (should be white as there is no vac cylinder fitted). main reservoir equalising pipe is yellow, the reg air (small pipe) white and the steam heat pipe should be silver.

hope this helps.

 

al Taylor

[buffalo]

Thanks, Al, that does help. Some of what I was calling white is presumably silver. Looking at the third pic on this page, my interpretation, reading from our left to right, is now:

 

Orange thing: MU socket?

Yellow fittings, white or silver tap above: air

Red fittings: vacuum

Silver fittings: steam heat

Yellow fittings, no tap visible, maybe hidden by buffer: air

Orange things: MU plug and cable?

 

In the other photo:

Red top of MU socket?

The first air pipe is obscured, but there looks to be either a white or yellow fitting hanging in about the right place.

Red fittings: vacuum

Hole in buffer beam where steam heat pipe has been removed (hadn't spotted this before).

Yellow fittings, white or silver tap above: air

Red things: MU plug and cable.

 

So, it would seem that most of this is in line with what you've said, but there seems to be no way to distinguish the two air pipes by colour and I can't see any difference in sizes in the photos.

 

Presumably, the brakes on the Hymek were operated by the air system? If so, what was the vacuum pipe for? At present, all I can imagine is that if a failed Hymek was rescued by a steam engine, then that could provide vacuum brakes to train that the Hymek was unable to brake... still somewhat confused

 

Nick

[Trainshed Terry]

Hi

 

The vac pipe is usually red (should be white as there is no vac cylinder fitted). main reservoir equalising pipe is yellow, the reg air (small pipe) white and the steam heat pipe should be silver.

hope this helps.

 

al Taylor

 

From the archives in my days when I worked on BR with Vac diesel multiple units,where still running it was Blue pipe Main or High side and the red was the brake pipe.

 

On diesel hauled Mk 1s there was only one vac pipe which was supposed to be red but nine time out of ten it was more rust in colour and the steam heat pipes where white..

 

As for Air braked passenger and EMU's rolling stock Red was the brake pipe and it was yellow for the main reservoir pipe.

 

Brake in the red pipe will bring the train to a stand.

 

Terry

[Fat Controller]

The vacuum brake was for the train- Hymeks weren't fitted with air-braking for that, though the loco brakes were air.

Brian

[buffalo]

Thanks, Brian, that makes more sense to me. However, if the air was not for train braking, why fit the pipes? Were the air pipes only used if multiple Hymeks were working together?

 

Nick

[Fat Controller]

Thanks, Brian, that makes more sense to me. However, if the air was not for train braking, why fit the pipes? Were the air pipes only used if multiple Hymeks were working together?

 

Nick

I wonder if they had something to do with that, or perhaps with the control systems, if the Hymeks were capable of multiple-working. I've just had a quick look at 'The Western's Hydraulics', which shows similar pipes on Warships, Westerns, 22s and 14s. In fact, the only photo where they were absent was the one of an ex-works 'Western Enterprise' on the cover.

There would have been an air-compressor and associated reservoir on board to start the engine, but it wouldn't have been powerful enough to supply train air brakes.

[buffalo]

According to therailwaycentre.com and Wikipedia, Hymeks were fitted with "Yellow Triangle" multiple control which enabled two of them to work together. The former site also mentions the second batch were fitted with "...Westinghouse brake equipment in place of Laycock Knorr..." The (air or vacuum?) tanks below and behind the buffer beams are visible in both photos on this site.

 

Nick

[cb900f]

Hi Nick

 

The yellow isolating cock/main res pipe was for filling the main reservoirs of other vehicles (assisting a failed train). There is a star valve in the end

 

The multiple jumper cable (multiple working) controlled the electrical contacts on the 2nd loco (forward/reverse,traction power etc).

 

The white isolating cock is the regulating air cock that enabled the driver to control more than one loco. The regulating air controlled the actual opening/closing of the fuel racks on the 2nd loco (RPM).No star valve fitted

 

 

 

The vacuum pipe was used to control the brakes on the train. On the loco the vacuum was converted to an air brake application by means of valves/relays. The name of which I have forgot.

 

Locomotives are not fitted with vacuum tanks. The vacuum is created by usually 2 exhausters which work all the time the loco is running, with the exception of when the reversing handle is placed to off. Going of the OP now.

 

Pete

[buffalo]

...Locomotives are not fitted with vacuum tanks. The vacuum is created by usually 2 exhausters which work all the time the loco is running, with the exception of when the reversing handle is placed to off. Going of the OP now.

 

Thanks, Pete. So are the tanks below the buffer beams air reservoirs? I've noticed that on some of the photos of preserved examples they are painted white and have small diameter white piping similar to that entering the brake actuators on the bogies.

 

No harm in going off the OP. I'm one of those people who like to understand the 'how' and 'why', even if my OP was only about the 'what'

 

The irony of all this is that apart from memories of my younger days, my only reason for having a Hymek is to haul unfitted mineral trains in the final years of the Somerset coalfield and for this, none of the pipes would be needed.

 

Nick

[cb900f]

Hi Nick

 

The colour coded systems used on a loco were as follows.

White air

brown fuel

salmon pink lube oil

blue water

red fire protection

Therefore the res under the bufferbeam would be main res but having never been trained on Hymeks it would have to be confirmed by someone who has.

I will have to pass on the small diameter pipe for the same reason.

 

 

Pete

[The Stationmaster]

(repeating some of what has already been said) The Hymeks were fitted with a straight air brake for loco braking and this was operated off the vacuum brake system via a proportional valve. Thus although the loco brakes were actually worked by air the control medium was the vacuum brake system hence it has red ends on the vacuum bags indicating that it is a braked vehicle. When the locos were worked in multiple the exhausters on the inside loco(s) were isolated to prevent them trying to create a vacuum when the train engine was applying the vacuum brake. The smaller diameter pipes with white cocks are the control air pipes used when the locos were attached to another loco.

I'm a little surprised about reference to the steam pipe being 'silver' as this was not the case when the locos were new although it is an understandable error as the steam pipes were standard issue and there had the couplings in a natural metal finish (as were the steam cock handles) although I suppose it is possible that they might have been given a touch of paint for some official photos. Somewhere I have some pics I took of new Hymeks soon after entering traffic and they definitely didn't have 'silver' steam pipe fittings. I'm not sure if I have a P&D guide for Hymeks but will have look in the most likely place in the day or two and see if there is one hidden away,

[keefer]

iirc the same layout of pipes could be found on many of the early diesels, the only difference often being the type of control jumper/socket used. i always used to wonder why these vacuum brake locos had main reservoir and control air pipes - i'd assumed it was all to do with the brakes, but know now that it's to do with the multiple control system too

[buffalo]

Many thanks to all, it's all much clearer than it was a few days ago

 

...Somewhere I have some pics I took of new Hymeks soon after entering traffic and they definitely didn't have 'silver' steam pipe fittings. I'm not sure if I have a P&D guide for Hymeks but will have look in the most likely place in the day or two and see if there is one hidden away,

 

If you can find any photos, Mike, that would be helpful. I'm very wary of all these colour photos of preserved engines.

 

Nick

[keefer]

a lovely pic of a new D7002 in 1961

 

b/w one of D7009 in 1961 from robert carroll's flickr

[buffalo]

a lovely pic of a new D7002 in 1961

http://www.flickr.co...boy/3372627995/

Excellent find! And yet another set of fiitings colours, yellow MU and white or bare metal everywhere else

Shed plate and horns on buffer beam, too.

 

b/w one of D7009 in 1961 from robert carroll's flickr

http://www.flickr.co...in/photostream/

Appears to have similar colours.

 

Interesting to see the air tanks painted white and no yellow paint on the wheel bearing covers.

 

Nick

[The Stationmaster]

Excellent find! And yet another set of fiitings colours, yellow MU and white or bare metal everywhere else

Shed plate and horns on buffer beam, too.

 

 

Appears to have similar colours.

 

Interesting to see the air tanks painted white and no yellow paint on the wheel bearing covers.

 

Nick

 

I think the colour might be a tad 'misrepresented' because of the red background on there on there Nick - as far as my memory serves the Hymek m.u connections were always orange on delivery. The shed plate on the bufferbeam was, of course, a feature of the early locos but I wonder if the mounting position and pre-drilled holes were present on every loco? Incidentally as far as the m.u connections were concerned I understood from various WR Inspectors who went up to Manchester to collect locos that the Hymeks were always tested in multiple by Beyer Peacock before they released the loco to BR and were to be found with the engine running waiting an on-site test before departure - a stark contrast with North British where it was apparently regarded as fairly miraculous that the loco was actually finished by the booked handover date and even less likely that it would work to spec it it was.