Why were the Deltics retired and not cascaded?

[Richard Scott]

Just out of interest what was their fuel consumption like? Two strokes are generally quite fuel hungry when run flat out for long periods. Wouldn't be surprised if this was also a contributing factor?

 

[hexagon789]

Interesting to hear that said of one of the fleet Deltics.

The excellent book "The Deltic Locomotives of British Rail" by Brian Webb (in the David & Charles Locomotive Studies series) has a final chapter on "Deltic Possibilites". Like most books in that series if you see a copy it's well worth a read.
This includes General Arrangement drawings of 6 suggested locomotives with Deltic engines, all credited to GEC Traction Ltd. These include a Class 50 style loco of 4400 or 4600 hp with a pair of Deltic 18s, and a Bo-Bo type derivation of the Class 55 of 2500hp with a single Deltic 18 at 2500hp.
Although digressing slightly from the theme of this thread this does show what had been considered possible for the Deltic engines.

Sounds like the so-called "Super Deltic" idea, a 4,400hp 110mph Deltic that would've been a bit like HS4000 Kestrel but with twin-engines.

Just out of interest what was their fuel consumption like? Two strokes are generally quite fuel hungry when run flat out for long periods. Wouldn't be surprised if this was also a contributing factor?

Only figure I can seem to find is 1.2gal/mi

 

[Stathern Jc]

Yes, it was referred to as the "Super Deltic". Quoted as 117 Tons, and the 2500hp Bo-Bo as 76 Tons when fitted with ETH rather than steam heating.

Interestingly, in the book in the same series on the Diesel Hydraulics, reference is made to a GA drawing sent by Maybach to the BRB of a 120 Ton variant of a Western fitted with 2 x 16 cylinder Hymek type engines set at their full rating of 2000hp, again offering a loco in the 4000hp bracket (with steam heating).
It also states that "shortly afterwards designs for single slow-speed engined diesel-electric locomotives of 4000hp began to circulate. Obviously including "Kestrel", but I'm not aware of anything else beyond what became the Class 56s. (Maybe a subject for another thread?)

 

[xotGD]

The Deltics could have had one engine removed to turn them into Type 3s and sent to Eastfield to work the West Highland.

Seems obvious with hindsight.

 

[hexagon789]

The Deltics could have had one engine removed to turn them into Type 3s and sent to Eastfield to work the West Highland.

Seems obvious with hindsight.

Though you would have ended up with something less powerful than a 37.

 

[randyrippley]

Yes, it was referred to as the "Super Deltic". Quoted as 117 Tons, and the 2500hp Bo-Bo as 76 Tons when fitted with ETH rather than steam heating.

Interestingly, in the book in the same series on the Diesel Hydraulics, reference is made to a GA drawing sent by Maybach to the BRB of a 120 Ton variant of a Western fitted with 2 x 16 cylinder Hymek type engines set at their full rating of 2000hp, again offering a loco in the 4000hp bracket (with steam heating).
It also states that "shortly afterwards designs for single slow-speed engined diesel-electric locomotives of 4000hp began to circulate. Obviously including "Kestrel", but I'm not aware of anything else beyond what became the Class 56s. (Maybe a subject for another thread?)

There's a passing comment somewhere on the web - can't remember where offhand - that the original plan for what became the class 50 was to use a Sulzer V-engine. The story goes that this would have been uprated from the class 48 engine to around 3000bhp, but Sulzer gave up on railway diesels after the 48 fiasco and lack of interest in Kestrel. They sold the rights to the V-engines to GEC who later used the technology in the 56/58 engines - mainly cylinder heads. But the 50 was left with an uprated standard EE block. No idea what the exact truth was, but makes an interesting what/if discussion

The Deltics could have had one engine removed to turn them into Type 3s and sent to Eastfield to work the West Highland.

Seems obvious with hindsight.

not really - you would have needed to add ballast equivalent to the removed engine to balance out the weight distribution

 

[DB]

They sold the rights to the V-engines to GEC who later used the technology in the 56/58 engines - mainly cylinder heads. But the 50 was left with an uprated standard EE block. No idea what the exact truth was, but makes an interesting what/if discussion

Isn't the engine in the 56 basically an updated version of the 50, with more or less the same block (and the 50 is an updated version of the 40, again with a very similar block).

not really - you would have needed to add ballast equivalent to the removed engine to balance out the weight distribution

And they'd still be a non-standard small fleet, with a very non-standard power unit.

 

[102 fan]

Wasn't there a plan to cascade to NIR, but they choose GM's instead?

 

[hexagon789]

Isn't the engine in the 56 basically an updated version of the 50, with more or less the same block (and the 50 is an updated version of the 40, again with a very similar block).

Yes, a close-ish relative you might say

 

[randyrippley]

Isn't the engine in the 56 basically an updated version of the 50, with more or less the same block (and the 50 is an updated version of the 40, again with a very similar block).

an EE block, but allegedly heads derived from Sulzer technology

 

[hexagon789]

Wasn't there a plan to cascade to NIR, but they choose GM's instead?

Other than the re-guaging issues, a lot more power than NIR really needed.

The CIÉ Enterprise was often allocated a single Baby GM of as little as 950hp, still quite capable of holding the 70 line limit and making the 2h15 timing that was the usual for the 1970s.

 

[102 fan]

A lot more power, but it would of been a great sound to hear!!!

 

[hexagon789]

A lot more power, but it would of been a great sound to hear!!!

Some would say the Irish GMs sound even better!

 

[randyrippley]

Only figure I can seem to find is 1.2gal/mi

its worth quoting from https://www.modelrailforum.com/forums/index.php?showtopic=897

I have only managed to locate one fuel consumption figure. It's from "The Deltics, A Symposium" Second revised edition published by Ian Allen. The figure is from a test run in November 1955 and the results were published in BTC Bulletin No. 19. The quote is as follows:

"On one of the runs a train of 20 coaches, grossing 642 tons, was taken over the test route with the engines at maximum power for as much as was possible within the prescribed speed limits. The sustained drawbar hp was around 2,200 and the 15 miles from Ormside to Ais Gill, largely at 1 in 100 up, were covered at an average speed of 56mph and a maximum speed of 50mph (sic). Fuel consumption for the run worked out at 1.27 gal/mile"

So there you have a 3,300hp prototype diesel pulling a heavy test train over a difficult route. It is probably on the high side, but it gives you somewhere to start. It is also worth pointing out that compared to other diesel engines of the time, the Napier Deltic was much higher revving at 1,650 rpm compared to the more modest 850rpm of the others.

this page gives details of specific fuel consumption of some of the marine versionsm but not the rail.
Its interesting to see the power the later models were delivering - by 1978 4140hp from a single 18-cylinder engine

Napier Deltic Opposed-Piston Diesel Engine

The Napier Deltic was a two-stroke, opposed-piston diesel engine with three cylinder banks arranged in a triangle. The engine was developed in the 1950s for marine and locomotive use, and it is sti…

oldmachinepress.com

 

[hexagon789]

its worth quoting from https://www.modelrailforum.com/forums/index.php?showtopic=897





this page gives details of specific fuel consumption of some of the marine versionsm but not the rail.
Its interesting to see the power the later models were delivering - by 1978 4140hp from a single 18-cylinder engine

Napier Deltic Opposed-Piston Diesel Engine

The Napier Deltic was a two-stroke, opposed-piston diesel engine with three cylinder banks arranged in a triangle. The engine was developed in the 1950s for marine and locomotive use, and it is sti…

oldmachinepress.com

Can you imagine the sound and acceleration from a twin-engined 8280hp Super-Duper Deltic?

 

[102 fan]

Some would say the Irish GMs sound even better!

No. Simply no.

 

[Anonymous10]

Can I ask what class the delitics were or have a link to a page on them

 

[DB]

Can I ask what class the delitics were or have a link to a page on them

55

 

[paul1609]

There have been numerous other examples too, including with traction far less obviously tempremental than a Deltic. Just look at the reliability variation with the same unit between different operators in the Golden Spanners statistics.

Isn't that just the politically correct way of explaining "Northern Monkey Syndrome"?

 

[hexagon789]

No. Simply no.

Each to their own I guess, as much as I may like Deltics I've never considered them the best sounding.

Can I ask what class the delitics were or have a link to a page on them

TOPS or its predecessor?

 

[randyrippley]

Isn't that just the politically correct way of explaining "Northern Monkey Syndrome"?

thats a bit uncalled for........take the 50s, Crewe got them working. Laira couldn't so all the "difficult" bits were stripped out and the locos rebuilt.
And when "difficult" means air filter, brakes, slow speed contol........something is wrong

 

[Richard Scott]

an EE block, but allegedly heads derived from Sulzer technology

Thought the 56 engine was almost pure EE heritage and cylinder heads were of EE decent but the 58 used the Sulzer technology? Happy to be corrected.
Thanks for info on Deltic engines - some interesting reading there.

No. Simply no.

Deltics definitely a unique sound with such a frequency range, almost like a high performance petrol engine (Alfa V6 engine always reminded me of Deltics with its low speed bass to high pitched yowl at high revs). Unsilenced GMs just sound like Maybachs albeit louder!!

 

[randyrippley]

Can I ask what class the delitics were or have a link to a page on them

there were two classes of Deltic, single engined ones and twin engined ones
the twin engined ones were used for Eastern Region expresses, details at https://en.wikipedia.org/wiki/British_Rail_Class_55
the single engined ones were used for local services and the diesels couldn't stand the repeated thermal cycling, details at https://en.wikipedia.org/wiki/British_Rail_Class_23

Thought the 56 engine was almost pure EE heritage and cylinder heads were of EE decent but the 58 used the Sulzer technology? Happy to be corrected.
Thanks for info on Deltic engines - some interesting reading there.

Possible my memory is faulty, but the point I was really trying to make is the 50s were a missed opportunity for a 3000+hp slow speed diesel using something based on the 48 and Kestrel engines

 

[Richard Scott]

Possible my memory is faulty, but the point I was really trying to make is the 50s were a missed opportunity for a 3000+hp slow speed diesel using something based on the 48 and Kestrel engines

Agree, I believe there were cases of 50s being set up on depots and not load banked and producing around 3000hp plus, making for some sprightly performances. If only they'd had alternators!

 

[paul1609]

thats a bit uncalled for........take the 50s, Crewe got them working. Laira couldn't so all the "difficult" bits were stripped out and the locos rebuilt.
And when "difficult" means air filter, brakes, slow speed contol........something is wrong

Hmm Im not sure "Janner Monkey Syndrome " justifies "Northern Monkey Syndrome" tbh

 

[randyrippley]

Can you imagine the sound and acceleration from a twin-engined 8280hp Super-Duper Deltic?

would a deltic engine fit into an HST power car?
I guess the problem would have been range though

 

[DB]

would a deltic engine fit into an HST power car?
I guess the problem would have been range though

It would fit - Deltic engines aren't large.

 

[Richard Scott]

would a deltic engine fit into an HST power car?
I guess the problem would have been range though

Probably, they're not that big. Begs the question would an MTU fit in a Deltic?!!!!!!!!

 

[randyrippley]

Probably, they're not that big. Begs the question would an MTU fit in a Deltic?!!!!!!!!

I read that seriously proposed once to get DELTIC powered again - it was claimed to be all that would fit.

If I remember correctly the story was the engines in DELTIC had steel crankcases and so were thinner walled than the alloy production ones, which were too wide to fit

 

[paul1609]

Probably, they're not that big. Begs the question would an MTU fit in a Deltic?!!!!!!!!

Almost certainly the Hunt class minesweepers that have been refitted with Cat c32 engines versus T9 Deltics (class 23) have an enormous amount of spare space in the engine room.