27/2's after Push Pull

delt1c · 6 Jan 2017

One thing I have never understood was why when the 27's were replaced on the Edinburgh - Glasgow service the 27/2's had the ETH removed and became effectively freight locos. Surely as the ETH was from a sepperate engine and not taking power from the main generator they would have been ideal for the West Highland line where 27's were still staple power albeit steam heat.

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rebmcr · 6 Jan 2017

delt1c said:
One thing I have never understood was why when the 27's were replaced on the Edinburgh - Glasgow service the 27/2's had the ETH removed and became effectively freight locos. Surely as the ETH was from a sepperate engine and not taking power from the main generator they would have been ideal for the West Highland line where 27's were still staple power albeit steam heat.

Perhaps the ETH generators were unreliable and/or inefficient to maintain?

Smudger105e · 6 Jan 2017

Separate engine? Were they now the same as the 33s where the main gen and the ETH gen were on the end of the same power unit?

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The Lad · 6 Jan 2017

Completely separate genset in the boiler compartment

Cowley · 6 Jan 2017

I'm no expert on this but from what I remember (I'd google it if I had time), the 27/2s had a separate air cooled Deutz engine that powered an alternator for the ETH. I think they were known to catch fire sometimes though which obviously was a major flaw

The 27/2s and 27/1s were pretty intensively thrashed on the Glasgow - Edinburgh trains too and perhaps were well past their best from the point of view of sending them out to the West Highlands on passenger services.

daikilo · 6 Jan 2017

Smudger105e said:
Separate engine? Were they now the same as the 33s where the main gen and the ETH gen were on the end of the same power unit?/QUOTE]

According to Wikipedia:
https://en.wikipedia.org/wiki/British_Rail_Class_27
The train heating boiler was replaced by a Deutz diesel engine driving an ETH generator.

In the same article there are hints as to why they were withdrawn (ETH conversions fire-prone, engines less reliable than those in class 26, blue asbestos ...). They were replaced on the Glasgow-Edinburgh push-pull by single class 47 with DBSO.

delt1c · 6 Jan 2017

Cowley said:
I'm no expert on this but from what I remember (I'd google it if I had time), the 27/2s had a separate air cooled Deutz engine that powered an alternator for the ETH. I think they were known to catch fire sometimes though which obviously was a major flaw
The 27/2s and 27/1s were pretty intensively thrashed on the Glasgow - Edinburgh trains too and perhaps were well past their best from the point of view of sending them out to the West Highlands on passenger services.

Yet the 27/1 continued on passenger service some being used on Aberdeen Inverness service.
It was a Duetz engine for ETH and they had some additional vents on the side

Smudger105e · 6 Jan 2017

I should have remembered that the 33s were the only type 3s built with ETH and no boiler. Thanks chaps.

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bnsf734 · 6 Jan 2017

Most Scottish Mk1 and early Mk 2 stock at this time was steam heat only, so the small pool of class 27/2 would have been an operational nightmare. Add to this their propensity to catch fire and the fact they were worn out after their stint on the Glasgow-Edinburgh service a nice retirement in freight service beckoned.

Of course this didn't stop them appearing in passenger service during the no-heat season as my scottish rovers netted quite a few.

47271 · 6 Jan 2017

I haven't checked but (explosions aside) I expect that another factor was that the ETH output of the 27/2 was pretty puny and far from future proof - the sets they ran with on the E&G were early mk2 and there was no aircon in the mix.

It was long before my time but it wouldn't surprise me if a lot of passengers experienced very cold journeys in winter on the route.

*Taunton* is very clued up on E&G push pulls of the era, he may be along soon...

Cowley · 6 Jan 2017

47271 said:
*Taunton* is very clued up on E&G push pulls of the era, he may be along soon...

I was thinking that, we were discussing them on a thread recently but I can't remember what it was now.

superkev · 6 Jan 2017

I remember riding on these. 8 motored axles and 2500hp pulling 5 lightweight mk2's where real flyers, up to 90mph in a breath. Very exillerating ride. Not sure how the gw-ed time compares with current or future.
K

hexagon789 · 6 Jan 2017

The generators fitted to the Class 27/2 were indeed very unreliable, prone to catch fire and rather under powered as mentioned above. A clue lies in the fact that the Mk2zs used on the service were dual-heat, the Class 27/1 used at the other end of the formation retained its steam-heat boiler, as the ETH generators were so unreliable that steam heat had to be retained as a back up. Another unusual feature of the Mk2zs was the braking system, at first look it seems like a usual twin-pipe air system but in addition to disc brakes being fitted, Girling WSP equipment and a unique two-stage system was employed. At speeds of over 60 mph the brake cylinder pressure was automatically increased to provide a consistent retardation rate from 90 mph to a stand. Full service braking was the norm with both the Class 27 push-pull sets and the later Class 47/7 sets. The frequency was half-hourly off-peak Mon-Sat in those days with services alternating between calling at Haymarket only or Falkirk High and Haymarket. This service and calling pattern continued but bizarrely the journey times were actually increased with the Class 47/7s, despite their 100 mph top speed. Services took 37 mins to Haymarket (41 to Waverley) non-stop and 39 mins to Haymarket (43 to Waverley) calling additionally at Falkirk High. The journey times for the Class 47/7 services were extended by 6 mins in both directions. At a mere 41 mins for a Haymarket only service from GLQ to Waverley (averaging an impressive 74.6 mph non-stop GLQ to Haymarket), the service was very definitely quicker than what the new Class 385s will achieve, albeit with a better service frequency and more stops. Also, the formation was six Mk2s, Class 27/1-TSO-TSO-TSO-TSO-FK-BSO-Class 27/2. The BSO was marshalled at the GLQ end and in later years with the van against the FK rather than the loco.

47271 · 6 Jan 2017

The only way you can do it in that time in a 170 is by skip stopping, now outlawed by the micromanagement of the Transport Minister. [emoji38]

I have done Haymarket to Queen Street once in the past ten years in 37mins, a preannounced skipper to recover from earlier delays. Falkirk was a blur.

superkev · 6 Jan 2017

hexagon789 said:
The generators fitted to the Class 27/2 were indeed very unreliable, prone to catch fire and rather under powered as mentioned above. A clue lies in the fact that the Mk2zs used on the service were dual-heat, the Class 27/1 used at the other end of the formation retained its steam-heat boiler, as the ETH generators were so unreliable that steam heat had to be retained as a back up. Another unusual feature of the Mk2zs was the braking system, at first look it seems like a usual twin-pipe air system but in addition to disc brakes being fitted, Girling WSP equipment and a unique two-stage system was employed. At speeds of over 60 mph the brake cylinder pressure was automatically increased to provide a consistent retardation rate from 90 mph to a stand. Full service braking was the norm with both the Class 27 push-pull sets and the later Class 47/7 sets. The frequency was half-hourly off-peak Mon-Sat in those days with services alternating between calling at Haymarket only or Falkirk High and Haymarket. This service and calling pattern continued but bizarrely the journey times were actually increased with the Class 47/7s, despite their 100 mph top speed. Services took 37 mins to Haymarket (41 to Waverley) non-stop and 39 mins to Haymarket (43 to Waverley) calling additionally at Falkirk High. The journey times for the Class 47/7 services were extended by 6 mins in both directions. At a mere 41 mins for a Haymarket only service from GLQ to Waverley (averaging an impressive 74.6 mph non-stop GLQ to Haymarket), the service was very definitely quicker than what the new Class 385s will achieve, albeit with a better service frequency and more stops. Also, the formation was six Mk2s, Class 27/1-TSO-TSO-TSO-TSO-FK-BSO-Class 27/2. The BSO was marshalled at the GLQ end and in later years with the van against the FK rather than the loco.

Thanks most interesting. Was the 41 min with the 27s or 47s. No idea what it is now or proposed. Progress eh.
K

hexagon789 · 6 Jan 2017

41 mins was Glasgow Queen Street to Edinburgh Waverley calling at Haymarket only with the Class 27 push-pull service. The same calling pattern was extended to 47 mins with the Class 47/7s despite the 10 mph increase in top speed.

47271 · 6 Jan 2017

To be fair to the current service it runs every 15 minutes, takes in two or three more intermediate stops and is only three or four minutes slower than the 47/7s.

What's quicker to Glasgow if I turn up at Waverley at my random convenience? A train that goes in up to half an hour's time, takes off like a scalded cat, and takes 41 minutes, or one that goes in no more than 15 minutes time and takes 49 minutes?

Added to that the 27s and 47s were chronically unreliable, especially towards the end of their respective periods of service. The 170s have been in charge for over 15 years now and are showing no signs of mechanically flaking out in their final 18-24 months.

Phil. · 6 Jan 2017

Smudger105e said:
Separate engine? Were they now the same as the 33s where the main gen and the ETH gen were on the end of the same power unit?

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Take off an ETS from the genny of a 1,250hp locomotive and there's not a lot left for traction.

dubscottie · 6 Jan 2017

47271 said:
To be fair to the current service it runs every 15 minutes, takes in two or three more intermediate stops and is only three or four minutes slower than the 47/7s.

What's quicker to Glasgow if I turn up at Waverley at my random convenience? A train that goes in up to half an hour's time, takes off like a scalded cat, and takes 41 minutes, or one that goes in no more than 15 minutes time and takes 49 minutes?

Added to that the 27s and 47s were chronically unreliable, especially towards the end of their respective periods of service. The 170s have been in charge for over 15 years now and are showing no signs of mechanically flaking out in their final 18-24 months.

The 47/7's were not unreliable but were in need of overhaul. They were the most intensively used locos on BR (except the class 59).

According to what was being said in a RailScene cabview video in a DBSO, it was the wiring in the coaches that caused problems.

On ETH from small locos.. The NIR 101's seemed to manage for years on the Belfast - Dublin turns.

hexagon789 · 7 Jan 2017

The beauty of the Class 47/7 push-pull system was its simplicity in transmitting the control signals through the coaches. The signals were sent through the train lighting circuits so any coach could be used in a push-pull set, and indeed all of Mk1 (admittedly only BGs, not general seating coaches), Mk2 and Mk3 appeared in the Aberdeen sets at one point or another. Really the let down of the system was its lack of finesse, only four power settings were available when the loco was propelling, rather than an infinitely variable control as in the loco, not the best in poor rail conditions!
--- old post above --- --- new post below ---
Also, the generator sets in the Class 27/2s provided the equivalent of 160 hp for heating, and no traction power was taken from the locos 933 hp at rail rating and while power-to-weight ratios aren't everything, a full Class 27/1-6 Mk2zs-Class 27/2 has a power-to-weight ratio of about 5 hp per ton, a Class 47/7-5 Mk3a-Mk2f DBSO has a power-to-weight ratio of 6.5 go per ton.

dubscottie · 7 Jan 2017

If I remember right, there was also a issue if a disc brake DBSO was on a rake of tread brake stock with the loco leading.

The brake in the DBSO would not release fully leaving stations so drivers would bring the train to a stop as usual, hold it using the locos brake, and overcharge the train brake to make sure nothing was dragging when they pulled away.

bnsf734 · 7 Jan 2017

I seem to remember that the 47/7 push-pull set on the Aberdeen run also used to have a Mk 1 buffet car included. Normally up against the loco so it could be easily removed when the set went onto other duties.

I also remember once leaving Aberdeen in the front coach of a Mk 2 Air conditioned set thinking the train was a bit draughty and then noted that the end doors had not been closed against the loco and a lot of fresh scottish air was being let in! We closed the doors and advised the guard that perhaps he ought to lock the doors!.

Memories.....

QueensCurve · 7 Jan 2017

hexagon789 said:
This service and calling pattern continued but bizarrely the journey times were actually increased with the Class 47/7s, despite their 100 mph top speed. Services took 37 mins to Haymarket (41 to Waverley) non-stop and 39 mins to Haymarket (43 to Waverley) calling additionally at Falkirk High. The journey times for the Class 47/7 services were extended by 6 mins in both directions. At a mere 41 mins for a Haymarket only service from GLQ to Waverley (averaging an impressive 74.6 mph non-stop GLQ to Haymarket), the service was very definitely quicker than what the new Class 385s will achieve, albeit with a better service frequency and more stops.

The Class 47/7/DBSO journey time was 48m Queen St to Waverly and reduced in about 1983 or 84 to 45m but reverting to the longer journey time later.

Smudger105e · 7 Jan 2017

Phil. said:
Take off an ETS from the genny of a 1,250hp locomotive and there's not a lot left for traction.

When I did my class 33 training as an apprentice, we were told that when the ETH was on, it used the equivalent of 2 of the Crompton's 8 cylinders, which would be somewhere around 400 horse power?

43096 · 7 Jan 2017

dubscottie said:
The 47/7's were not unreliable but were in need of overhaul. They were the most intensively used locos on BR (except the class 59).

Class 43s were, and still are, more intensively utilised.

Whistler40145 · 7 Jan 2017

I remember reading an article that when BR was introducing the Push-Pull service with 27s, they were also looking at using Class 37s and Class 50s were also considered.

I also read that at one point, the Class 27 fleet availability wasn't up to 100% and it wasn't unusual for Classes 25/26 to substitute for an unavailable 27.

gimmea50anyday · 7 Jan 2017

In comparison to today a 170 produces around 7hp per ton while a 180, 185 and voyager are hitting around 9hp per ton.

A 33 on ETH still puts into the rail a similar amount of power to that produced by 4 EE507's as typically used on most 4 car SR EMUs, although they proved they had the power to shift a load 8 or 9 on the mule without hurting the schedule too much

I think as with a 47 there was an additional power setting that shut down the ETS temporarily and put full engine output into the traction motors.

Whistler40145 · 7 Jan 2017

If the Scottish Region had got it's way, we would've seen 33s working on the West Highland line, but found they were far too heavy for the infrastructure and the Southern wouldn't release any.

matchmaker · 7 Jan 2017

TimSYoung40145 said:
I remember reading an article that when BR was introducing the Push-Pull service with 27s, they were also looking at using Class 37s and Class 50s were also considered.

I also read that at one point, the Class 27 fleet availability wasn't up to 100% and it wasn't unusual for Classes 25/26 to substitute for an unavailable 27.

I've seen a 37 at one end of a push-pull set.

superkev · 7 Jan 2017

I seem to remember the 47/7 pushed trains were nicknamed discos as the control for the locos was via the lighting circuits which caused the lights to flicker as the loco notched up.
K

27/2's after Push Pull

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