The mighty Class 74 (some questions!)

[Acathater]

Apologies that this is likely 71, not 74, related... 3-4 years ago now, whilst perusing boat train photos of the 1960s and early 1970s, one image-result was an electric blue liveried class 71 (presume) pre-TOPS era.
My memory cannot recall if the train was Night Ferry, Golden Arrow, or another boat train.

I have yet to find that image again. Does it ring any bells? Do you know which loco was painted thus? It looked stunning.

was it CC2 / 20002?

from https://sremg.org.uk/electric/class70.shtml

From 1949/50 they adopted the initial black and aluminium colour scheme chosen by British Railways for diesel, electric and gas turbine locomotives, however prior to this in 1948/9 N°20002 carried an experimental light blue livery and was exhibited in this colour to the railway executive at Kensington Addison Road station.

 

[Sun Chariot]

was it CC2 / 20002?

The photo I found, was definitely a JA

 

[Big Jumby 74]

The photo I found, was definitely a JA

HA ?

 

[Sun Chariot]

HA ?

Oh yes - I always get my HAs and JAs mixed!

 

[D7666]

I had assumed it was 91 <>92, so thank you for the gentle correction

The post 1974 core Rep working cycle in the basic off peak pattern was from

Waterloo Down 91 Weymouth
Bournemouth Up 91 Weymouth
Waterloo Down 92 Bournemouth
Bournemouth Up 92 Bournemouth
Waterloo

So, Up from Bournemouth, after the TC were attached to the Rep, each combined 4Rep/8TC remained together to Waterloo on a 91, then a 92 to Bomo and back complete train, then the next 91 Down to Bomo, where the Rep detached. Repeat.

Before the pedants dive in and start listing exceptions, of course start of day, end of day, morning peak, evening peak, weekends, etc etc had numrous variations.

Pre 1974 was a little different in that the 91s were bi hourly and the 92s hourly, i.e. 3 trains every 2 hours, but they were still hourly to Weymouth - the bi hourly Weymouth 91s alternated with a bi hourly Weymouth 92.

 

[Harlequinuk]

Does anyone know of a Frank 'Mad Monk' Matthews? Been reading he had a reputation for pushing a loco , and holds the unofficial speed record in a 74?

 

[hexagon789]

Does anyone know of a Frank 'Mad Monk' Matthews? Been reading he had a reputation for pushing a loco , and holds the unofficial speed record in a 74?

I seem to recall mention of him, the nickname rather sticks, on rmweb or possibly another forum.

He was indeed reputed to have got (IIRC) 120mph out of a 74...

 

[D6130]

I seem to recall mention of him, the nickname rather sticks, on rmweb or possibly another forum.

He was indeed reputed to have got (IIRC) 120mph out of a 74...

Was he a Waterloo (ex-Nine Elms) driver?

 

[hexagon789]

Was he a Waterloo (ex-Nine Elms) driver?

That, I'm not sure about.

I'll see if I can find the thread/post on the other forum.

 

[Undaunted]

The book ‘The twilight of Southern steam’ by Don Benn contains a few references to Frank Matthews, which suggest that he wasn’t averse to working locomotives extremely hard. Sadly, the same book refers to his death in a collision between two engineering trains at West Brompton on 29 July 1989 (accident report available on the Railways Archive website). The report refers to the driver involved as ‘T Matthews’, but Don Benn seems to know the Nine Elms drivers involved in the end of steam on the SW main line well, so I have no reason to think he would get such an important detail wrong.

I believe he was based at Waterloo at the time of the accident.

 

[Cowley]

Thread reopened for @Harlequinuk to add to

 

[Harlequinuk]

Hey all, got a request. Been reading that the original `clean sheet` design for the Class 74 was aiming to have a much larger and more powerful engine (possibly a paxman V12), to make it a true type2 on diesel to complement the type 4 electric power , and was wanted by W.J.A Sykes before the government shot him down. Apparently it was also discussed by A. Hawes at the IEE in 1975?

I don`t suppose anyone has anything concrete, maybe a schematic or 2?

 

[D6130]

Hey all, got a request. Been reading that the original `clean sheet` design for the Class 74 was aiming to have a much larger and more powerful engine (possibly a paxman V12), to make it a true type2 on diesel to complement the type 4 electric power , and was wanted by W.J.A Sykes before the government shot him down. Apparently it was also discussed by A. Hawes at the IEE in 1975?

I don`t suppose anyone has anything concrete, maybe a schematic or 2?

IEE ?

 

[Sun Chariot]

IEE ?

Institute of Electrical Engineers?

 

[D6130]

Institute of Electrical Engineers?

Thanks! Should have thought of that - or Googled it - but it's still a bit early in the morning for me!

 

[Acathater]

Hey all, got a request. Been reading that the original `clean sheet` design for the Class 74 was aiming to have a much larger and more powerful engine (possibly a paxman V12), to make it a true type2 on diesel to complement the type 4 electric power , and was wanted by W.J.A Sykes before the government shot him down. Apparently it was also discussed by A. Hawes at the IEE in 1975?

I don`t suppose anyone has anything concrete, maybe a schematic or 2?

Hard to believe it would fit

 

[Harlequinuk]

Hard to believe it would fit

It was a clean sheet design, not a rebuild of the 71 ; however the government of the day (and the mandarins at Southern), wanted to reuse the 71s out of traffic, so the plans wernt progressed. Instead the paxmann V6 was fitted instead . https://steamindex.com/jile/jile50.htm WJA Sykes wanted a far more powerful design to handle boat trains, as the 600 bhp `HA` was underpowered.

 

[D7666]

I'm pretty sure the late A.T.H.Taylor (who's experience stretched from 10201 & co through DEMU and D6500s and all EDLs) told me the proposed engine was the Paxman 12YJXL i.e. the V12 from the same model range (per D830 and the D6100 rebuilds) as the 6YJXL used in 74s (and 14s); that would make it 1300 hp in direct proportion or 1350 hp at its contemporary BR traction setting.

I suspect it was space reasons led to V6 not V12 in the 74s as rebuilt and not the new design - not so much engine size space but cooling capacity - you need double the radiator size, double everything and there was not much space in a 74 as it was.

The Paxman YJ "Ventura" range

Paxman Ventura (YJ) Diesel Engines

Paxman History - Applications and Despatches of Paxman Ventura Engines

www.paxmanhistory.org.uk

was very highly thought of by BR engineers unfortunately arrived too late to be of much use in BRs diesel fleet. It can be thought of as the lineal predecessor to the Valenta (RP200) indeed the early Valentas were designated Y3J (mk3 YJ).

There were also V8 and V16 versions from Paxman but BR did not take either; only one V16 traction example was built, for export, and no traction V8; the V16 ad V8 were however much used in marine and power generation.

I supposed the V8 might have been looked at for EDL and in proportion would have come out at 867 hp; have never seen evidence to that effect.

 

[Harlequinuk]

I'm pretty sure the late A.T.H.Taylor (who's experience stretched from 10201 & co through DEMU and D6500s and all EDLs) told me the proposed engine was the Paxman 12YJXL i.e. the V12 from the same model range (per D830 and the D6100 rebuilds) as the 6YJXL used in 74s (and 14s); that would make it 1300 hp in direct proportion or 1350 hp at its contemporary BR traction setting.

I suspect it was space reasons led to V6 not V12 in the 74s as rebuilt and not the new design - not so much engine size space but cooling capacity - you need double the radiator size, double everything and there was not much space in a 74 as it was.

The Paxman YJ "Ventura" range

Paxman Ventura (YJ) Diesel Engines

Paxman History - Applications and Despatches of Paxman Ventura Engines

www.paxmanhistory.org.uk

was very highly thought of by BR engineers unfortunately arrived too late to be of much use in BRs diesel fleet. It can be thought of as the lineal predecessor to the Valenta (RP200) indeed the early Valentas were designated Y3J (mk3 YJ).

There were also V8 and V16 versions from Paxman but BR did not take either; only one V16 traction example was built, for export, and no traction V8; the V16 ad V8 were however much used in marine and power generation.

I supposed the V8 might have been looked at for EDL and in proportion would have come out at 867 hp; have never seen evidence to that effect.

I believe there was another consideration - the use of the booster/generator. Instead of having a system ala HA, the engine simply replaced the flywheel, which of course was another reason the V6 was anaemic , it had to drive an additional series of moving parts before power got near the motors. Which would explain the 315 bhp at teh rails from a 650 bhp paxman (where the EE 4pot in the 73 made 388 at the rail from 600 bhp). I think i read the cooling group would be more akin to a 47 to cool the V12 Paxman?

 

[D6130]

I'm pretty sure the late A.T.H.Taylor (who's experience stretched from 10201 & co through DEMU and D6500s and all EDLs) told me the proposed engine was the Paxman 12YJXL i.e. the V12 from the same model range (per D830 and the D6100 rebuilds) as the 6YJXL used in 74s (and 14s); that would make it 1300 hp in direct proportion or 1350 hp at its contemporary BR traction setting.

I suspect it was space reasons led to V6 not V12 in the 74s as rebuilt and not the new design - not so much engine size space but cooling capacity - you need double the radiator size, double everything and there was not much space in a 74 as it was.

The Paxman YJ "Ventura" range

Paxman Ventura (YJ) Diesel Engines

Paxman History - Applications and Despatches of Paxman Ventura Engines

www.paxmanhistory.org.uk

was very highly thought of by BR engineers unfortunately arrived too late to be of much use in BRs diesel fleet. It can be thought of as the lineal predecessor to the Valenta (RP200) indeed the early Valentas were designated Y3J (mk3 YJ).

There were also V8 and V16 versions from Paxman but BR did not take either; only one V16 traction example was built, for export, and no traction V8; the V16 ad V8 were however much used in marine and power generation.

I supposed the V8 might have been looked at for EDL and in proportion would have come out at 867 hp; have never seen evidence to that effect.

Shame....there were 19 nearly-new Paxman Ventura V12XJYL engines available when they scrapped the 29s.

 

[D7666]

I believe there was another consideration - the use of the booster/generator. Instead of having a system ala HA, the engine simply replaced the flywheel, which of course was another reason the V6 was anaemic , it had to drive an additional series of moving parts before power got near the motors. Which would explain the 315 bhp at teh rails from a 650 bhp paxman (where the EE 4pot in the 73 made 388 at the rail from 600 bhp). I think i read the cooling group would be more akin to a 47 to cool the V12 Paxman?

I am saying it was A that determined B, you are saying B determined A.

The booster sook up that space (and weight) that could otherwise have been used for a bigger engine. That comes before power output of the whole drive line because without that set (taking up space and weight) the output power would be different. The underlying reason for the small engine is space and weight with the set .

ITYF if you scroll back it was me who pointed out (see msg 27) in this thread the power at rail values.

47 original was 2750 hp which is double that of the 12YJ at 1300/1350 hp => the cooler group for the V12 Paxman would be half the size of that in a 47.

 

[Acathater]

The booster set took up that space (and weight) that could otherwise have been used for a bigger engine

No, the booster set was removed to make space for the diesel engine. There wasn't any room for anything bigger

 

[D7666]

Shame....there were 19 nearly-new Paxman Ventura V12XJYL engines available when they scrapped the 29s.

Not sure BR worked like that.

It can equally be suggested there were already a number of the V6 YJ engines from early D9500 withdrawals maybe not actually withdrawn in 1966/67 but already in store pending disposal. Yet the 74s had new engines. While it is true BR sold many D9500s into industry that needed to keep their engines, I suspect they generated far less cash from selling 11 complete D9500s than buying 11 new engines,


err what did the engine drive if it were not the booster set then ?

74s retained booster but now electronic controlled

 

[Acathater]

I think you are confused.

The booster set is a motor generator set on a common shaft, with a flywheel on that shaft in a 71; the 74 did not have the flywheel, just the m-g set.

Yes I seem to have been
I reported my post and requested it be deleted before you posted

 

[D7666]

I reported my post and requested it be deleted before you posted

ok got it now we were posting in parallel hence the further confusion

 

[Helvellyn]

Class 75 is sometimes referenced as reserved for a super ED. Was this ever the case, or at some point has someone picked up on what Sykes originally wanted and just assigned Class 75 to it, when in reality it should really be 74(i), 74(ii) being the 71 rebuilds?

 

[Romsey]

Not sure BR worked like that.

It can equally be suggested there were already a number of the V6 YJ engines from early D9500 withdrawals maybe not actually withdrawn in 1966/67 but already in store pending disposal. Yet the 74s had new engines. While it is true BR sold many D9500s into industry that needed to keep their engines, I suspect they generated far less cash from selling 11 complete D9500s than buying 11 new engines,


err what did the engine drive if it were not the booster set then ?

74s retained booster but now electronic controlled

First of all , the booster sets were removed from the 71's on conversion to 74's to provide room for the Paxman diesel and radiators
As mentioned upstread the electronics were a one off as it seemed to be the way forward. Odd for the Southern CM&EE who often seemed to be at the tail end of any technology changes.
I'm sure the tale has been told about the Paxman engines in the 74's and 14's that there was an issue with saving weight. Cast iron engine blocks were used but with aluminium cylinder heads. Remember your "O" level physics and coefficients if expansion? It didn't end well with many blown gaskets and pulled securing studs... That's why the Coal Board and British Steel rebuilt the maxman engines in their second hand class 14's with cast iron cylinder heads.

They were also banned from working Freightliner trains after a short experiment. Attached to coaching stock with a buckeye coupler damped down most of the movement in the loco. With soft oleo buffers of the locos and the Freightliner outer wagons there was very little resistance to up and down movements however tight the screw coupling was do.adjusted. They were rostered for the daytime Willesden to Millbrook Freightliner for a few weeks. They kept time and could haul the trains just fine, but the crews ended up seasick! So it was back to a pair of class 33's.

 

[Harpo]

First of all , the booster sets were removed from the 71's on conversion to 74's to provide room for the Paxman diesel and radiators
As mentioned upstread the electronics were a one off as it seemed to be the way forward. Odd for the Southern CM&EE who often seemed to be at the tail end of any technology changes.
I'm sure the tale has been told about the Paxman engines in the 74's and 14's that there was an issue with saving weight. Cast iron engine blocks were used but with aluminium cylinder heads. Remember your "O" level physics and coefficients if expansion? It didn't end well with many blown gaskets and pulled securing studs... That's why the Coal Board and British Steel rebuilt the maxman engines in their second hand class 14's with cast iron cylinder heads.

They were also banned from working Freightliner trains after a short experiment. Attached to coaching stock with a buckeye coupler damped down most of the movement in the loco. With soft oleo buffers of the locos and the Freightliner outer wagons there was very little resistance to up and down movements however tight the screw coupling was do.adjusted. They were rostered for the daytime Willesden to Millbrook Freightliner for a few weeks. They kept time and could haul the trains just fine, but the crews ended up seasick! So it was back to a pair of class 33's.

On coupling to freightliners generally - I’ve a niggling memory from the 80s that you couldn’t use the loco coupling on liners and that a missing wagon coupling needed the ‘red’ emergency screw coupling to be used??

 

[Tony73E]

First of all , the booster sets were removed from the 71's on conversion to 74's to provide room for the Paxman diesel and radiators
As mentioned upstread the electronics were a one off as it seemed to be the way forward. Odd for the Southern CM&EE who often seemed to be at the tail end of any technology changes.
I'm sure the tale has been told about the Paxman engines in the 74's and 14's that there was an issue with saving weight. Cast iron engine blocks were used but with aluminium cylinder heads. Remember your "O" level physics and coefficients if expansion? It didn't end well with many blown gaskets and pulled securing studs... That's why the Coal Board and British Steel rebuilt the maxman engines in their second hand class 14's with cast iron cylinder heads.

They were also banned from working Freightliner trains after a short experiment. Attached to coaching stock with a buckeye coupler damped down most of the movement in the loco. With soft oleo buffers of the locos and the Freightliner outer wagons there was very little resistance to up and down movements however tight the screw coupling was do.adjusted. They were rostered for the daytime Willesden to Millbrook Freightliner for a few weeks. They kept time and could haul the trains just fine, but the crews ended up seasick! So it was back to a pair of class 33's.

The booster sets were not removed on conversion as that is how the locos worked on both diesel and electric. The one-ton flywheels (used to provide more rotational energy to the mass of the motor and generator) were removed to save weight. To provide room for the Paxman engine, the booster set had to be moved longitudinaly in what was now an the engine room.
Unlike a Class 73 where the diesel and electric ends are seperate entities control wise (although parts of the electric main starting resistance grids are used during diesel transistion), the booster set on a Class 74 was either powered from the conductor rail or, at reduced power, from the diesel engine.

 

[Harlequinuk]

First of all , the booster sets were removed from the 71's on conversion to 74's to provide room for the Paxman diesel and radiators
As mentioned upstread the electronics were a one off as it seemed to be the way forward. Odd for the Southern CM&EE who often seemed to be at the tail end of any technology changes.
I'm sure the tale has been told about the Paxman engines in the 74's and 14's that there was an issue with saving weight. Cast iron engine blocks were used but with aluminium cylinder heads. Remember your "O" level physics and coefficients if expansion? It didn't end well with many blown gaskets and pulled securing studs... That's why the Coal Board and British Steel rebuilt the maxman engines in their second hand class 14's with cast iron cylinder heads.

They were also banned from working Freightliner trains after a short experiment. Attached to coaching stock with a buckeye coupler damped down most of the movement in the loco. With soft oleo buffers of the locos and the Freightliner outer wagons there was very little resistance to up and down movements however tight the screw coupling was do.adjusted. They were rostered for the daytime Willesden to Millbrook Freightliner for a few weeks. They kept time and could haul the trains just fine, but the crews ended up seasick! So it was back to a pair of class 33's.

The booster sets were retained in place , but the flywheel was removed

https://digital-library.theiet.org/doi/abs/10.1049/piee.1975.0225?utm_source=chatgpt.com

Thats a link to a paper by by A.Hawes and the flywheel was replaced by The Paxman engine an an EE843 diesel generator.