Imaginary Locomotives

[Flying Pig]

4 hours ago, ScottishRailFanatic said:

Here's an idea - what about a modified EMD F7? It would be shortened in terms of height and width in order to fit our loading gauge, and probably given Blue Pullman-style fronts and cabs and made to work in pairs - an early HST of sorts?

 

Plenty of EMD derivatives were built with two cabs, which would be more useful over here - see for example the NOHAB locomotives built in Sweden and used in a number of European countries.

[BernardTPM]

And the classic Australian VR Class B on which the Tri-ang R159 was loosely based.

[AlfaZagato]

I think the NOHAB jobs might just fit, or just not.

[Flying Pig]

3 hours ago, Northmoor said:

The Super Deltic actually got to the drawing board stage.  It was to be 2x2200hp Deltic engines in a Class-50-like body.

 

What about an HS4000-like body? That was a very handsome machine but perennially overweight.  Solve the problem with a couple of svelte Deltics

[The Johnster]

3 hours ago, ScottishRailFanatic said:

Random idea, how about a 1Co-Co1 'Super Deltic', like an amalgamation of LMS 10000 and a Class 55? Would that be able to be used on the ECML?

Instead of the DP1 1955 prototype perhaps?  It would be capable of ECML work, as of course the production Deltics were in reality, but I'm not sure the concept fits in to what EE were doing in the mid to late 50s.  The problem was still at that time the provision of generators of sufficient capacity, of low enough all-up weight, and small enough size to fit into the UK loading gauge and within the axle loading limit (25t).  It was this that engendered the WR's affair with hydraulics, and that led to the Co-Bo arrangement of the Metrovicks, and the plethora of Type 2s capable of being driven in multiple.  It was fairly easy to build a Type 2 in the late 50s and to believe it was powerful enough; it wasn't, for reasons I will come back to.

 

If you look at it from the perspective of the 1955 Modernisation Plan, what was required was a fleet of diesel locomotives to replace steam by 1970.  The information that the tenders to British industry were based on was the power ratings obtained from testing steam locomotives at the new Rugby Testing Plant, and these were, apparently, not a reflection of the actual power that those locos could put out.  It had been determined that 8P steam power equated to about 2k bhp, and 7MT to about 1.8k bhp. 

 

So, the early Modernisation Plan diesels (I'm going to call them MP for brevity) were ordered in 4 'type' power bands.  They were stipulated to be a) British or build in the UK under licence,  b) based on proven equipment and practice, and c) capable of multiple control from one traincrew in the leading cab.  Now, let us consider the diesel electrics that preceeded them, the Ivatt twins and the Bullied 1Co-Co1s (Fell was an interesting dead end).  Ivatt had studied US diesel electric practice and sailed home with the view that a loco of about 1.6k bhp could equate the work of a Black 5 and 2 of them in mulitple that of a Coronation, and decided that the engine should put out 1.600hp.  My view is that events proved him ultimately correct.

 

EE, GEC originally, had produced a power plant with a 1.6k output to the generator, which Ivatt used successfully in the twins.  Bullied wanted more from a single loco, and this engine was uprated to 1.8k bhp to be used in multiple on 10101/2, which could work in mulitple, and extended to 2k bhp for 10103, which couldn't.  But they were monsters, 1Co-Co1s weighing 140 tons or so!  10103 was the basis of the MP's class 40, a loco intended to be capable of replacing 8P steam.  They were very quickly shown to be incapable of replacing 7MT Britannias out of Liverpool Street.  The basic framework was adapted for use with a Sulzer 2.5k bhp power unit in the Peak classes, equally monstrously heavy and long, and none of them could work in multiple.

 

1955 MP proved hopeless at replacing 8P steam power, but EE in the same year got it half right with the 3.3k bhp Deltic, ordered in production for the ECML to replace their pacifics.  I say half right, because the Deltics broke 2 of the MP's stipulations, being unprovenly equipped and not capable of working in multiple.  They were prima donnas, not owned for some time by BR and maintained at Doncaster by EE engineers.  They were big beasts, and would have been beyond the loading gauge for general use, but eventually saw service on the trans pennine route as well as Leeds and ECML.  Steam timings were not significantly bettered by them, any timetable reductions coming from track realignments and upgrading, and they were spectacularly noisy and dirty; we loved them for this, but it did not endear them to the non-enthusiast world. They were, in short, not an unqualified success.  Real improvements to what steam could do had to wait until the HST, a pattern followed on other routes.

 

A 'Superdeltic' was argualby not needed, and certainly I doubt that it would have taken the form of a 1Co-Co1.  A twin Co-Co+Co-Co or an articulated twin unit might have been able to put out 6.6k, but there was no work for it.  The Superdeltic Class 50 style loco was to be a 4.4k bhp+ loco based on an enlarged and uprated DP2.  The Class 50 was a bit of an emergency stop gap for the WCML which had had it's Weaver Jc-Motherwell electrification postoponed in 1966 and needed a 5.4k power source for it's promised timetable improvements.  There was no diesel loco over 1.75k bhp that could be driven in multiple in 1966, and the DP2 concept was modified to provide one, the control gear giving much trouble in service.

 

I would also suggest that, had the MP been aware of the real horsepowerage needed to equal, never mind better, steam performance with a bit of reserve to improve reliability and avoid the thrashing that destroyed the Warships and Canton's Hymeks (replaced Kings on the Paddingtons, come on...), the smallest locos would have been the Class 33 BRCW pocket rocket, Type 3 in a Type 2 bodyshell, capable of multiple working, brilliant little thing, and, notably, the same bhp as a single Ivatt twin.  Nothing smaller was much use to be honest; the trip and pickup/branch work they'd been designed for and were anyway underpowered for was no longer there within a decade on the MP.  Of course,  the MP did not have the benefit of our 20/20 hindsight and were working, as I said, from flawed and incorrect Rugby information. 

 

Had it been a 1962 MP, we might have seen steam lasting until the early 70s and a railway based more or less on on 37s and 47s and 25kv 86s, with the 47s being capable of multiple working with the 37s and each other, a combination which could have handled any job on the railway with the 47s derated to 2.3k bhp for reliability.  RR engined Class 17s would have done everything else, including replacing 08s which were not capable of replacing steam on trip work without getting in the way; too slow!  37/47 double headed multiple power would have been 4.05k bhp for a weight of 222tons, very reliable, and performance comparable to a Deltic (700+bhp more power but more dead weight.  If we can uprate the 47 without compromising reliability the situation improves.  This would be a phenomenally reliable setup in service; better than double heading 42s on the West of England main line or 50s on the WCML.  No primadonna Deltics, dead end hydraulics, underpowered 40s, overweight Peaks, or pointless Type 2s.

 

The day was saved eventually by the completion of the ECML and WCML electrifications and, elsewhere, by the HST, which I rate as the best main line passenger train ever built in the UK.  My time on  the railway included it's introduction; we were all very proud of it.  It was generally held that the MP diesels were underpowered and unreliable, and that the 'second generation' of supercharged locos with lightweight but powerful generators were much better but that the increasingly heavy freight work had yet to better the 9F's performance.  Anything below Type 3 was really useless for the post Beeching railway's needs, though Class 20s hunting in pairs nose to nose on MGRs did all right.  Hawker Siddley (Brush) came up with Kestrel, which looked like what we wanted; a 4k bhp 125mph loco that could be geared for heavy freight.  We were a bit off target, and the 56s and 58s that followed were not as good as they should have been.  We now have 125mph 67s and 68s, but nobody seems to quite know why..

 

DP1, the blue Deltic, was a pretty ground breaking beast in 1955.  It was trialled on the Turbomotive's old job, the 10.00 LIverpool-Euston, known to be one of the heaviest and toughest in the country, and romped away with it.  It's styling, already a bit retro even in those days, belied it's modernity.  But the Deltics were only regarded as a success because they were alone among pre-HST diesels in being able to reliably and easily equal 8P steam power without double heading.  There are other good reasons for adopting diesel over steam, of course, but the travelling public are unaware of them and unconcerned with them; they want cheap fares and reliable timetables.  HSTs gave them that and got them there quicker than driving on increasingly gridlocked motorways, and gave them comfier than Pullman seats, soundproofing, air suspension, airco, electric heating and microwaved BLT toasties at no extra fare.  Run rings around any Deltic, and more reliable as well.

Edited March 5, 2021 by The Johnster

[AlfaZagato]

I don't mean to undermine your excellent post, yet I feel the biggest issue - anywhere, let's be honest - in dieselizing was being unable to make a logical leap to play to the real strengths of ICE or electric power.  

 

Here in the US, we're basically playing the MR's 'small engine' policy, though more of a 'medium engine' policy.   I live on the former CN&W main line.   We rarely, if ever, see the real crazy SD70mac or SD90's.   We mostly get SD45s and the GE equivalent.   Maybe an SD40 once in a blue moon.   With modern MU working, there really isn't need to build 'supers' anymore.

 

I actually find it funny that you in the UK seem to still be chasing large single locomotives to do the work.

[The Johnster]

It's a bit of a paradox, AZ, but our sidings, loops, reception roads and so on are much shorter than yours, our loading gauge is not far off half the size of yours, and our axle loads are limited to 25tons.  We do not have the lengthy single track sections you have out west that need long trains to maximise pathing capacity.  Since the 60s, our freight work has proportionately been ever-increasing numbers of block mineral, steel, chemicals, and point-to-point intermodals, loaded to the maximum possble length permissible with our short sidings, passing loops, reception roads, and loading/unloading facilities, and shorter distances for signalling clearances in order to run at higher speeds.  Maximising pathing on our overcrowed and near capacity network requires freight trains that can make 75mph point to point timinsg with 3kton loads and stay out of the way of the passenger traffic, which on the main lines is ruuning at between 110 and 140mph. 

 

Your multi-loco lashups of less powerful single unit locos spread throughout the train would mean that perhpas a dozen or more high capacity 100ton glw bogie wagons would have to be omitted from the consist or the train would be overlength.  So, we are committed to what we consider to be big and powerful diesel electric locos (since about half of our trunk route network remains to be electrified) that can pull a 3kton 75mph train, Co-Cos of about 4 or 5 khp rating.  Most of them are US designed; our workhorse Class 66 comes from EMD in Ontario.  When they are unloaded from the ships, the crane drops them on to the bogies, some connections are made, they are filled with diesel, batteries installed, and driven off  the dock about an hour tops after unloading.

 

You probably consider this sort of power band to be medium at the most, but they are much more powerful than the locos of the 1955 MP or for several subsequent decades.  The idea of multiple lashups that is so much a part of your scene was a part of early diesel development here, in fact much of our early efforts were very much influenced by the US diesels of the 40s and 50s, the Fs, GPs, Fairbanks Morses, and all  that classic retro stuff.  Our railway managers, planners, and politicians had all been much impressed with your streamlined airconditioned passenger trains and awesome freight hauls, and some of them seem to have overlooked the limitations of UK operation.  Extending loops and sidings is less easy and much more expensive in this crowded nation where land usage is intense and land prices high even in areas of comparitively low population, which prevents much in the way of expansion of railway real estate; indeed, much of the old massive steam age areas of sidings and yards have been sold off, back in the 70s and 80s, by a railway starved of cash and eager to rid themselves of the assets.

 

Our early diesels showed US influence in the provision of cab doors to facilitate multiple working, but we did not go down the road of single cab A or cabless B units.  Many of our lower powered attempts were similar in appearance to your 'road switchers' but the work they were intended for, local trip, pickup, and branch freight, was largely disposed of after our "Beeching Report' (Google Dr. Richard Beeching) of 1963 which led to the closure of branch lines, the thing it is most remembered for, but also and arguably more importantly the closure of hundreds of smaller main line stations  and their goods depots in favour of centralising general goods traffic at large urban centres.  This was a gift to the road haulage industry, already doing well as our motorway network spread; local passenger traffic was assumed to be all in private cars, and much was by the mid 70s, but the motorways, bypasses, and other new roads were full and congested, there was little land available to expand them, and passenger traffic began to return to the railway. 

 

Stations, but not goods depots because the space is needed for car parking, have re-opened and whole routes are being re-instated, but our railway is now as congested as our motorway network and we are in a hole, but nobody knows how to stop digging.  It is difficult from a US, or Canadian, viewpoint to appreciate how overcroweded the UK is, but flying over it at night is a very illuminating experience, literally; there are none of the dark open spaces one sees on mainland Europe and no places such as you have that side of the pond where no lights can be seen at all from 35,000 feet on a clear night.  I flew over Labrador in 1985; it was something of a culture shock!

[Northmoor]

2 hours ago, The Johnster said:

EE, GEC originally, had produced a power plant with a 1.6k output to the generator, which Ivatt used successfully in the twins.  Bullied wanted more from a single loco, and this engine was uprated to 1.8k bhp to be used in multiple on 10101/2, which could work in mulitple, and extended to 2k bhp for 10103, which couldn't.  But they were monsters, 1Co-Co1s weighing 140 tons or so!  10103 was the basis of the MP's class 40, a loco intended to be capable of replacing 8P steam.  They were very quickly shown to be incapable of replacing 7MT Britannias out of Liverpool Street.  

 

Nothing smaller was much use to be honest; the trip and pickup/branch work they'd been designed for and were anyway underpowered for was no longer there within a decade on the MP.   

 

Had it been a 1962 MP, we might have seen steam lasting until the early 70s and a railway based more or less on on 37s and 47s and 25kv 86s, with the 47s being capable of multiple working with the 37s and each other, a combination which could have handled any job on the railway with the 47s derated to 2.3k bhp for reliability.  

 

The day was saved eventually by the completion of the ECML and WCML electrifications and, elsewhere, by the HST, which I rate as the best main line passenger train ever built in the UK.  My time on  the railway included it's introduction; we were all very proud of it. 

 

Anything below Type 3 was really useless for the post Beeching railway's needs, though Class 20s hunting in pairs nose to nose on MGRs did all right.  

 

A few points there in your excellent post @The Johnster that I'll respond to.

 

I was only last night dipping into the David & Charles volume on EE Diesels and it says some interesting things about the 40s and their predecessors.  I didn't know that one 40 was intended to be uprated to 2400hp (with supercharging); 20% more power and virtually no weight increase would have addressed a lot of the complaints about them being overweight.  Also, while I have heard many stories about them not being able to improve on the Britannias on the Norwich run, their ability to out-accelerate them to Stratford and clear Brentwood bank at nearly 60mph endeared them to the crews and the operating department.  Presumably though the biggest benefit was to the latter who could send them back and forth all day, unlike the steamers....  I've often wondered if the 10000/10001 design uprated to 2000hp in the same body (or would the electrics not have coped?) whether they could have made a much more effective locomotive than the 40s developed from them.

 

Type 2s with no purpose?  Probably true except in the Highlands of Scotland, except that if as you suggest, 33s had become a standard design, they would have been built in big numbers instead of 26s/27s (which ironically, are extremely useful diesels for most preserved lines).

 

Derating 47s to 2300hp... they were already derated to 2580hp for reliability purposes.  They are much maligned but 47s with a 2750hp EE engine (not a Sulzer 12LDA nearing the end of it's development life) would have been a very effective tool and rendered the 50s pointless.

 

HST: your comment I have "emboldened" as I cannot think of a statement about our railways that I agree with more strongly.

 

20s in pairs turned out to be a very economic solution on a lot of short MGR turns up to the early 90s.  Some years before they were modernised by DRS, there was a very interesting MR article by Roger Ford on the feasibility of re-engining the 20s with modern CAT power for perhaps 1350hp, which it was believed the motor insulation could cope with.  Although Uncle Roger didn't say so, a small, faster-revving engine might have allowed the radiator to be relocated, creating space for a second cab.....

[PhilJ W]

6 minutes ago, Northmoor said:

20s in pairs turned out to be a very economic solution on a lot of short MGR turns up to the early 90s.  Some years before they were modernised by DRS, there was a very interesting MR article by Roger Ford on the feasibility of re-engining the 20s with modern CAT power for perhaps 1350hp, which it was believed the motor insulation could cope with.  Although Uncle Roger didn't say so, a small, faster-revving engine might have allowed the radiator to be relocated, creating space for a second cab.....

A twin cabbed 20, now there's a thought.

[Compound2632]

2 minutes ago, PhilJ W said:

A twin cabbed 20, now there's a thought.

 

Well, that was easily done by coupling them nose to nose. Twice as powerful, too.

[Ramblin Rich]

2 hours ago, Northmoor said:

....  I've often wondered if the 10000/10001 design uprated to 2000hp in the same body (or would the electrics not have coped?) whether they could have made a much more effective locomotive than the 40s developed from them.

 

Type 2s with no purpose?  Probably true except in the Highlands of Scotland, except that if as you suggest, 33s had become a standard design, they would have been built in big numbers instead of 26s/27s (which ironically, are extremely useful diesels for most preserved lines).

 

Derating 47s to 2300hp... they were already derated to 2580hp for reliability purposes.  They are much maligned but 47s with a 2750hp EE engine (not a Sulzer 12LDA nearing the end of it's development life) would have been a very effective tool and rendered the 50s pointless.

 

HST: your comment I have "emboldened" as I cannot think of a statement about our railways that I agree with more strongly.

 

 

I've always thought the Ivatt twins were proto-37s so in that case, 2000hp versions of 37s should also be possible.

Class 33 was the best thing BRCW produced, it really should have been made in bigger numbers especially as ETH replaced steam heat. A shame that the work put into 'Lion' and the narrowed 33/2 sent the company to the wall.

Would Brush have collaborated with EE to re-engine the 47s? It preempts the 56s in a way as their Ruston-Paxman engine is the offspring of EE's CSVT range. EDIT- of course, 47 601 was the test bed for those engines so would also be a first approximation of this idea

Again, agree HST was, and still is, best and last BR passenger train!

Edited March 5, 2021 by Ramblin Rich
clarification

[Flying Pig]

3 hours ago, AlfaZagato said:

I actually find it funny that you in the UK seem to still be chasing large single locomotives to do the work.

 

British locos built since the 1990s are largely comparable to the SD45 in power and that seems to be sufficient for most of the traffic without widespread multiple working.

[Murican]

Just a thought with all my LNER superpower steam ideas: if there are only six each of the P2s and I1s, how many of the W2 4-6-4s could we see? Could they possibly replace the A4s of real life as the the A3's successor?

[Northmoor]

1 hour ago, Ramblin Rich said:

I've always thought the Ivatt twins were proto-37s so in that case, 2000hp versions of 37s should also be possible.

 

Hey there's another thing - what happened to the experimental uprating to 2000hp of 37292 in the 1980s?  I've seen the photos of it in works when the work was being done but never heard whether the trials were successful.  Whatever, it was obviously reversed and no further locos were converted.

[rodent279]

15 hours ago, The Johnster said:

Instead of the DP1 1955 prototype perhaps?  It would be capable of ECML work, as of course the production Deltics were in reality, but I'm not sure the concept fits in to what EE were doing in the mid to late 50s.  The problem was still at that time the provision of generators of sufficient capacity, of low enough all-up weight, and small enough size to fit into the UK loading gauge and within the axle loading limit (25t).  It was this that engendered the WR's affair with hydraulics, and that led to the Co-Bo arrangement of the Metrovicks, and the plethora of Type 2s capable of being driven in multiple.  It was fairly easy to build a Type 2 in the late 50s and to believe it was powerful enough; it wasn't, for reasons I will come back to.

 

If you look at it from the perspective of the 1955 Modernisation Plan, what was required was a fleet of diesel locomotives to replace steam by 1970.  The information that the tenders to British industry were based on was the power ratings obtained from testing steam locomotives at the new Rugby Testing Plant, and these were, apparently, not a reflection of the actual power that those locos could put out.  It had been determined that 8P steam power equated to about 2k bhp, and 7MT to about 1.8k bhp. 

 

So, the early Modernisation Plan diesels (I'm going to call them MP for brevity) were ordered in 4 'type' power bands.  They were stipulated to be a) British or build in the UK under licence,  b) based on proven equipment and practice, and c) capable of multiple control from one traincrew in the leading cab.  Now, let us consider the diesel electrics that preceeded them, the Ivatt twins and the Bullied 1Co-Co1s (Fell was an interesting dead end).  Ivatt had studied US diesel electric practice and sailed home with the view that a loco of about 1.6k bhp could equate the work of a Black 5 and 2 of them in mulitple that of a Coronation, and decided that the engine should put out 1.600hp.  My view is that events proved him ultimately correct.

 

EE, GEC originally, had produced a power plant with a 1.6k output to the generator, which Ivatt used successfully in the twins.  Bullied wanted more from a single loco, and this engine was uprated to 1.8k bhp to be used in multiple on 10101/2, which could work in mulitple, and extended to 2k bhp for 10103, which couldn't.  But they were monsters, 1Co-Co1s weighing 140 tons or so!  10103 was the basis of the MP's class 40, a loco intended to be capable of replacing 8P steam.  They were very quickly shown to be incapable of replacing 7MT Britannias out of Liverpool Street.  The basic framework was adapted for use with a Sulzer 2.5k bhp power unit in the Peak classes, equally monstrously heavy and long, and none of them could work in multiple.

 

1955 MP proved hopeless at replacing 8P steam power, but EE in the same year got it half right with the 3.3k bhp Deltic, ordered in production for the ECML to replace their pacifics.  I say half right, because the Deltics broke 2 of the MP's stipulations, being unprovenly equipped and not capable of working in multiple.  They were prima donnas, not owned for some time by BR and maintained at Doncaster by EE engineers.  They were big beasts, and would have been beyond the loading gauge for general use, but eventually saw service on the trans pennine route as well as Leeds and ECML.  Steam timings were not significantly bettered by them, any timetable reductions coming from track realignments and upgrading, and they were spectacularly noisy and dirty; we loved them for this, but it did not endear them to the non-enthusiast world. They were, in short, not an unqualified success.  Real improvements to what steam could do had to wait until the HST, a pattern followed on other routes.

 

A 'Superdeltic' was argualby not needed, and certainly I doubt that it would have taken the form of a 1Co-Co1.  A twin Co-Co+Co-Co or an articulated twin unit might have been able to put out 6.6k, but there was no work for it.  The Superdeltic Class 50 style loco was to be a 4.4k bhp+ loco based on an enlarged and uprated DP2.  The Class 50 was a bit of an emergency stop gap for the WCML which had had it's Weaver Jc-Motherwell electrification postoponed in 1966 and needed a 5.4k power source for it's promised timetable improvements.  There was no diesel loco over 1.75k bhp that could be driven in multiple in 1966, and the DP2 concept was modified to provide one, the control gear giving much trouble in service.

 

I would also suggest that, had the MP been aware of the real horsepowerage needed to equal, never mind better, steam performance with a bit of reserve to improve reliability and avoid the thrashing that destroyed the Warships and Canton's Hymeks (replaced Kings on the Paddingtons, come on...), the smallest locos would have been the Class 33 BRCW pocket rocket, Type 3 in a Type 2 bodyshell, capable of multiple working, brilliant little thing, and, notably, the same bhp as a single Ivatt twin.  Nothing smaller was much use to be honest; the trip and pickup/branch work they'd been designed for and were anyway underpowered for was no longer there within a decade on the MP.  Of course,  the MP did not have the benefit of our 20/20 hindsight and were working, as I said, from flawed and incorrect Rugby information. 

 

Had it been a 1962 MP, we might have seen steam lasting until the early 70s and a railway based more or less on on 37s and 47s and 25kv 86s, with the 47s being capable of multiple working with the 37s and each other, a combination which could have handled any job on the railway with the 47s derated to 2.3k bhp for reliability.  RR engined Class 17s would have done everything else, including replacing 08s which were not capable of replacing steam on trip work without getting in the way; too slow!  37/47 double headed multiple power would have been 4.05k bhp for a weight of 222tons, very reliable, and performance comparable to a Deltic (700+bhp more power but more dead weight.  If we can uprate the 47 without compromising reliability the situation improves.  This would be a phenomenally reliable setup in service; better than double heading 42s on the West of England main line or 50s on the WCML.  No primadonna Deltics, dead end hydraulics, underpowered 40s, overweight Peaks, or pointless Type 2s.

 

The day was saved eventually by the completion of the ECML and WCML electrifications and, elsewhere, by the HST, which I rate as the best main line passenger train ever built in the UK.  My time on  the railway included it's introduction; we were all very proud of it.  It was generally held that the MP diesels were underpowered and unreliable, and that the 'second generation' of supercharged locos with lightweight but powerful generators were much better but that the increasingly heavy freight work had yet to better the 9F's performance.  Anything below Type 3 was really useless for the post Beeching railway's needs, though Class 20s hunting in pairs nose to nose on MGRs did all right.  Hawker Siddley (Brush) came up with Kestrel, which looked like what we wanted; a 4k bhp 125mph loco that could be geared for heavy freight.  We were a bit off target, and the 56s and 58s that followed were not as good as they should have been.  We now have 125mph 67s and 68s, but nobody seems to quite know why..

 

DP1, the blue Deltic, was a pretty ground breaking beast in 1955.  It was trialled on the Turbomotive's old job, the 10.00 LIverpool-Euston, known to be one of the heaviest and toughest in the country, and romped away with it.  It's styling, already a bit retro even in those days, belied it's modernity.  But the Deltics were only regarded as a success because they were alone among pre-HST diesels in being able to reliably and easily equal 8P steam power without double heading.  There are other good reasons for adopting diesel over steam, of course, but the travelling public are unaware of them and unconcerned with them; they want cheap fares and reliable timetables.  HSTs gave them that and got them there quicker than driving on increasingly gridlocked motorways, and gave them comfier than Pullman seats, soundproofing, air suspension, airco, electric heating and microwaved BLT toasties at no extra fare.  Run rings around any Deltic, and more reliable as well.

I've always thought that rather than the multiple different types of diesel introduced under the Modernisation Plan, what BR really needed was a fleet of 20's, 37's and 40's. That would take care of all but the fastest and heaviest passenger, and heaviest freights, which could be handled with either double heading, or something more powerful/speedier, like Deltics. Effectively, the HST did the former, as it is really two locos double heading a fixed formation of stock, it's just that the locos are either end rather than coupled together at one end.

A Duchess will typically develop about 3-3300ihp, which equates to some 2-2500hp at the rail. To do that with a diesel requires a minimum of 3300bhp, remembering that bhp is the power developed by the engine, at the flywheel. After accounting for transmission and auxiliary losses, that 3300bhp becomes around 2500hp at the rail. So a 47, with a shade under 2000hp at the rail, is little better than a King or Castle in good nick.

What a diesel can't do that steam, and electric for that matter, can, is exceed it's continuous rating for a short while. A diesel's power output is fixed, and can't be exceeded for a short time, steam can produce high short term power outputs, but at the expense of boiler pressure. Electric can do the same, the limiting factor being the temperature rise in the equipment.

I suspect that someone in the BTC got their bhp & rail hp mixed up, and also overlooked the fixed power output of a diesel. 

Edited March 6, 2021 by rodent279

[ScottishRailFanatic]

Here’s a question - remember the Stanier Conqueror concept? How quickly could that realistically go?

[Suzie]

I think that early experience with the 40s should have inspired a project to produce some single cab 40s that would be used in pairs where more than 2000 HP was required. It might have inspired a HST type arrangement made from a pair of these 40s and a rake of Mk1s in the 1950s. Now that would have left its mark given how long Mk1s and 40s remained in service, probably only being displaced on the Highland main line with the cascading of the more modern HSTs.

 

I guess they would have had a 1C0-C0 wheel arrangement being a bit shorter without the cab and nose at the back.

[rodent279]

2 minutes ago, Suzie said:

I think that early experience with the 40s should have inspired a project to produce some single cab 40s that would be used in pairs where more than 2000 HP was required. It might have inspired a HST type arrangement made from a pair of these 40s and a rake of Mk1s in the 1950s. Now that would have left its mark given how long Mk1s and 40s remained in service, probably only being displaced on the Highland main line with the cascading of the more modern HSTs.

 

I guess they would have had a 1C0-C0 wheel arrangement being a bit shorter without the cab and nose at the back.

By the time the 40's were built, it ought to have been possible to fit that 2000hp kit into a Co-Co, something like a class 37/Deltic hybrid. I imagine a 1-Co-Co-1 single ended loco would be a bit ungainly. It must be bad enough driving a class 20 the "wrong" way,  a 40 is significantly longer.

[Suzie]

Perhaps like this one in a later livery, smaller fuel tank being as the load will be shared between the two locos.

[Clive Mortimore]

29 minutes ago, Suzie said:

I think that early experience with the 40s should have inspired a project to produce some single cab 40s that would be used in pairs where more than 2000 HP was required. It might have inspired a HST type arrangement made from a pair of these 40s and a rake of Mk1s in the 1950s. Now that would have left its mark given how long Mk1s and 40s remained in service, probably only being displaced on the Highland main line with the cascading of the more modern HSTs.

 

I guess they would have had a 1C0-C0 wheel arrangement being a bit shorter without the cab and nose at the back.

Without a cab and traction motor blower?

[Suzie]

Well, it might need a bit of fettling...

 

... perhaps there could be some blowing from the other end? Perhaps lose the other cab?

[rodent279]

Something like a stretched class 20 on 3 axle bogies might work.

[PhilJ W]

3 minutes ago, rodent279 said:

Something like a stretched class 20 on 3 axle bogies might work.

With a cab at each end? Then it becomes a class 58.

[Flying Pig]

2 hours ago, rodent279 said:

By the time the 40's were built, it ought to have been possible to fit that 2000hp kit into a Co-Co, something like a class 37/Deltic hybrid. I imagine a 1-Co-Co-1 single ended loco would be a bit ungainly. It must be bad enough driving a class 20 the "wrong" way,  a 40 is significantly longer.

 

That would have pushed the axle load up to 22t compared to 16-17t for a class 37 or 40 as built. The LMS of course fitted an EE 16SVT and generator into a Co-Co locomotive, also giving an axle load of about 22t, though the engine could only give 1600hp at that time. 

 

[Clive Mortimore]

3 minutes ago, Flying Pig said:

 

That would have pushed the axle load up to 22t compared to 16-17t for a class 37 or 40 as built. The LMS of course fitted an EE 16SVT and generator into a Co-Co locomotive, also giving an axle load of about 22t, though the engine could only give 1600hp at that time. 

 

Brush later fitted the 3, 250 hp uprated version into a Co-Co At a tad over 20t per axle in the class 56.