Why were the Peaks considered redundant?

[Lacathedrale]

I've read in the 'what if the Pilot Scheme was allowed to Run' thread in the discussion forum, and would just like to confirm the reasoning why so many people have written there that the 44/45/46's were essentially obsolete in favour of the 47. Is it purely a cost/power comparison, or is there something else to it? I'm reminded of the wonderful video on YT about the Peaks:

 

 

[Miss Prism]

The power-to-weight ratio of the 47 was significantly better than the route-restricted 44/45.

 

The Peaks were handsome, though.

 

[phil-b259]

I believe the main issue is weight. The class 47 had the same power output as the Peaks but but were much lighter. Other things like the lack of a 'nose' on the 47s would have also made driver visibility from the cab, particularly at close range, better too.

[The Johnster]

A 47 weighed 117tons, and a Peak came in at 142, with the 47 being slightly more powerful even after the 47's Sulzer spindizzy was derated by 100hp,, the difference being 'about a coach'.  Put another way, a 47 could haul a train with an extra coach or 2 loaded 16ton minerals or equivalent compared to a Peak to the same timings, or the same train to faster timings.  The Peak bogies were very long wheelbase, shared with the class 40 and Southern Railway designed diesel-electrics, and were thus restricted from some sidings and yard roads because of sharp curvature.  The driver's view ahead was better from the 47 cab, and the 47 was a lot shorter, so you could get more of them on to a shed road.

 

The Peaks were good engines, though, and what I regard as the best run of my railway career (Canton guard in the 70s) featured a 45, sadly can't recall the number now.  Gloucester Tramway to Cardiff Pengam Freightliner recep., full load 1,290tons, all speed restrictions properly observed, start to stop 54 miles in 57 minutes.

 

The ride was excellent with low mileage bogies but deteriorated over time, with the springs bottoming out which ISTR led to frame cracking being detected by ultrasonics, and this may have been a factor in the decision to withdraw the Peak classes, as well as the 40s.

[andyman7]

Remember too that the 47s were built afterwards so were in any case younger. Many of the Peaks had long careers for BR modernisation plan locos. The 10 x Class 44s were non-standard so went in the late 1970s which still gave them close to a 20 year career; the 46s and 45/0s were next, going in the late 70s and first half of the 80s; whilst the 45/1s were superseded when the MML was resignalled and equipped with HSTs having achieved at least 25 years service.

 

20-25 years was pretty much the maximum life of the modernisation plan diesels without heavy overhaul/life extension. The 31s, 37s and 57s (ex-Class 47) that have gone on to have very long careers were all subject to such overhauls and/or re-engining.

Edited October 28, 2021 by andyman7

[TheSignalEngineer]

25 minutes ago, andyman7 said:

20-25 years was pretty much the maximum life of the modernisation plan diesels without heavy overhaul/life extension. The 31s, 37s and 57s (ex-Class 47) that have gone on to have very long careers were all subject to such overhauls and/or re-engining.

I suspect all that remains of the original in most cases is the frame and bodywork. Every loco from the start of time has become a Trigger's Broom after about 10 years. 

[The Stationmaster]

3 hours ago, Miss Prism said:

The power-to-weight ratio of the 47 was significantly better than the route-restricted 44/45.

 

The Peaks were handsome, though.

 

But equally the earlier design had the advantage of additional weight when it came to handling partly fitted freights where weight was important in providing brake power.  But basically the 'Peaks' (various marks thereof) were an early Modernisation Plan design which was gradually improved with higher horsepower etc while the Brush type 4 was a second generation(ish) design which took advantage of various changes plus getting rid of the 'nose'.  Oddly though in terms of originally built reliability the Brush Type 4s were a major disaster area which took a lot of time and modifications to get them to a useful level of reliability while by the time of the Class 46 build the earlier design was pretty reliable as it came  off the assembly line.

[Flying Pig]

1 hour ago, The Johnster said:

The Peak bogies were very long wheelbase, shared with the class 40 and Southern Railway designed diesel-electrics, and were thus restricted from some sidings and yard roads because of sharp curvature.

 

More importantly perhaps, the design had no secondary suspension, being mounted to the locomotive body by rigid pivots which would be a significant part of the hard ride when run down, as well as presumably increasing track forces.

 

I don't know why EE and Derby stuck with these bogies for their type 4s: EE managed a double bolster 1-Co bogie for the Rhodesian Railways DE2 (diagram) which entered service in 1955 with a 16SVT engine.  That was on Cape gauge track too, though the overall weight was a little lower and only 60mph was required.

[The Johnster]

Our 47s were pretty reliable by the 1970s, but had taken a good bit of work and an engine derating to get to that stage.  In those days, the longevity of a loco depended on it's overall numbers, then it's ability to carry air brakes and their related pokery-jiggery, and then a little later to do the same with eth equipment and a head power source for airco.  The Warships, Baby Warships, and Hymeks would have fallen at the air brake hurdle and the Westerns at the eth/airco hurdle even had BR not decided to eliminate hydraulic transmissions in the early 70s and standardise on diesel electrics.  The original reason for the WR's adoption of hydraulics was that generators capable of handling higher power outputs within the axle load and loading gauge limitations were rare as rhs in the late 50s, but the situation had improved significantly by the early 60s.  The class 44 Peaks were the most powerful diesel locos owned by BR when they were introduced.

 

So by the 70s there were plenty of relatively lightweight '2nd generation' Type 4 Co-Cos of around the 117ton mark with supercharged engines, in the form of over 500 47s and 50 50s.  This enabled BR to easily eliminate the Type 4 hydraulics, which would have been of limited further use anyway.  The Peaks were a slightly different issue, and I always thought of them as a sort of half way house between first and second generation diesel electrics, a class 40 with a more up to date, powerful, and efficient prime mover.  Like the 40s, the cab styling evolved from the 1955 plan gangwayed pattern, through a spit headcode version, to a central 4-character headcode box, a 1960s idea that was coming to the end of it's life a decade later.

 

The demise of the Peaks and the 40s a decade later was a response to more modern heavy freight locos coming into service, the extension of 25kv electrification, and the continuing fall in freight traffic.  As Mike Stationmaste has noted, the 40s and the Peaks had a deadweight advantage in the working of part-fitted main line freight trains, which were becoming increasing thin on the ground by then.  There were too many Type 4 diesels whose work had passed to HSTs or electrics, and the core Peak territory, the MML, had gone to HSTs so these were the locos next in line for withdrawal.  This was IMHO no excuse to run one at high speed into a nuclear flask, a piece of pure vandalism which might have been more justified had it included research into the impact survivabliity of the mk1 stock, a missed opportunity.

 

The bogies were a direct consequence of the 1955 Plan.  In 1955, there were few diesel bogies that had proved themselves in service, and the heavy 1-Co had done so with the Southern's 10101/2/3.  The bogie from the Ivatt twins found it's way beneath the EM2 electrics and the D600 Warships, but was not considered up to the weight of the class 40 and Peak behemoths.  It was heavy and added a lot to the considerable all-up weight of these locos, and the long fixed wheelbase was not kind to sharp curves, as well as being prone to hairline fractures. 

 

A hard riding bogie is not just a matter of being uncomfortable for the train crew; the shaking and continual shocks it generates cause damage throughout the loco which manifests itself in worn engine mountings, split pipe unions, and loose fittings everywhere.  It also introduces draughts everywhere in the cab, so that as well as the crew having their spines hammered they are frozen as well.  It does not do any good to the per. way either.  Too soft, as on the 47s, and short wheelbase, as on the production Warships and the Westerns, is just as damaging.  I found the EE bogie from the 37s, also used on the Deltics and 50s, to be a good compromise, but the best ride was from the long wheelbase Commonwealth on the Hymeks.  The absolute worst was the torture of the Class 25s, which should have been speed restricted to 60mph IMHO; they were frankly alarming a 90mph!

[Rivercider]

The retention of drivers traction knowledge will also play a part. Class 47s were seen right across BR so I imagine would have been one of the standard traction classes to learn at most traincrew depots.

In the West Country once Laira had lost the class 46 allocation, and class 45 appearances west of Plymouth became rare it was necessary in 1983 to specifically provide one class 45 weekday diagram to and from Penzance to help retention of traction knowledge. From about 1986 there was no diagrammed work for the remaining class 45s west of Bristol, although they still got west on some out and back diagrams, to Meldon Quarry for example

 

cheers

Edited October 28, 2021 by Rivercider
clarification

[Titan]

On the 1Co-Co1 bogies, the pony truck was unbraked, so most of the extra weight did not contribute much to the brake force - very little to choose between the brake force of a 45 and a 47, 63 tons v 61.

[Rivercider]

15 minutes ago, The Johnster said:

 

 

A hard riding bogie is not just a matter of being uncomfortable for the train crew; the shaking and continual shocks it generates cause damage throughout the loco which manifests itself in worn engine mountings, split pipe unions, and loose fittings everywhere.  It also introduces draughts everywhere in the cab, so that as well as the crew having their spines hammered they are frozen as well.  It does not do any good to the per. way either.  Too soft, as on the 47s, and short wheelbase, as on the production Warships and the Westerns, is just as damaging.  I found the EE bogie from the 37s, also used on the Deltics and 50s, to be a good compromise, but the best ride was from the long wheelbase Commonwealth on the Hymeks.  The absolute worst was the torture of the Class 25s, which should have been speed restricted to 60mph IMHO; they were frankly alarming a 90mph!

I agree that the class 37 was a very successful class, but when they were introduced into Cornwall on the clay branches there were more derailments in certain areas on severe curves, compared to the class 25s I understand. Horses for courses I would suggest. 

 

cheers

[The Johnster]

2 hours ago, Titan said:

On the 1Co-Co1 bogies, the pony truck was unbraked, so most of the extra weight did not contribute much to the brake force - very little to choose between the brake force of a 45 and a 47, 63 tons v 61.

Good point, but the strength of the 1Co-Co1 classes was that their great weight enabled them them to brake more effectively than lighter classes on which the wheels would skid under heavy brake applications with unbraked or part braked trains, one of the reasons for the provision of diesel brake tenders, which were basically a bogie vacuum braked vehicle stuffed full of concrete ballast with a low enough profile for the driver to see over the top of it when it was being propelled.  Brake force is a slightly different consideration.

[Zomboid]

4 hours ago, TheSignalEngineer said:

I suspect all that remains of the original in most cases is the frame and bodywork. Every loco from the start of time has become a Trigger's Broom after about 10 years. 

I doubt the engine etc are original, especially after the ETH conversion, but there are an awful lot of bits of 45132 which have D22 stamped on them.

[Phil Bullock]

The logic of Peaks being more competent at braking unfitted trains has more than a ring of truth yet there are plenty of photos of Peaks with brake tenders …. 

Wiktionary brake tender

 

Edited October 28, 2021 by Phil Bullock

[The Johnster]

40s, too.  Possibly because the tenders worked to diagrams or certain trains were booked to include them?

 

At Canton, we used them more or less as freely interchangeable alternatives for 47 jobs.  They were rare on the North to West line, our 'Hereford run', and less common west of Cardiff than to it's east, and were pretty much 50/50 with 47s on the Gloucester road.  I liked them; they did their work without making a song and dance about it and had a lot of character compared to the rather bland styling of the 47s.  As an ex-spotter from the 60s, I always regarded them as 'Midland engines' but they weren't, and became less so in later times.  Their styling was a bit dated but the performance was very much 2nd generation.

[TheSignalEngineer]

2 hours ago, Zomboid said:

I doubt the engine etc are original, especially after the ETH conversion, but there are an awful lot of bits of 45132 which have D22 stamped on them.

And I expect many have been refettled over the years. In 1968 I was rebuilding signalling equipment at Crewe which had originally been manufactured as far back as the 1880s.

[The Johnster]

On a diesel locomotive, I would expect it to be usual for the bogies, wheels, frames and/or body to be original, along with the cabs and control equipment.  Diesel engines, generators, pumps, compressors, filters, valves, etc. are all designed to be ‘changed out’, taken out of the loco and replaced by refurbished equipment so that the loco can be pit back into traffic.  Such components are then stripped down, repaired, refurbished or replaced, and go into stores ready to be put on to the next loco that comes into the depot for servicing. 
 

This means that the bogies and bodies/frames, drawgear, buffers, and more of 31s, 37s, and 47s still in service are around 60 years old, as are significant parts of 57s.  

Edited October 29, 2021 by The Johnster

[37114]

3 hours ago, The Johnster said:

On a diesel locomotive, I would expect it to be usual for the bogies, wheels, frames and/or body to be original, along with the cabs and control equipment.  Diesel engines, generators, pumps, compressors, filters, valves, etc. are all designed to be ‘changed out’, taken out of the loco and replaced by refurbished equipment so that the loco can be pit back into traffic.  Such components are then stripped down, repaired, refurbished or replaced, and go into stores ready to be put on to the next loco that comes into the depot for servicing. 
 

This means that the bogies and bodies/frames, drawgear, buffers, and more of 31s, 37s, and 47s still in service are around 60 years old, as are significant parts of 57s.  

Many locos when subjected to a works overhaul ended up being stripped down to just a shell so are unlikely to have the original bogies and wheels they left the factory with, albeit the bogies they are sat on will have been built at the same time, they were just originally fitted to another loco of the same class or in some case a different class. eg some class 37's gained Deltic bogies when the Deltic's were withdrawn for example.

[Phil Bullock]

2 hours ago, 37114 said:

Many locos when subjected to a works overhaul ended up being stripped down to just a shell so are unlikely to have the original bogies and wheels they left the factory with, albeit the bogies they are sat on will have been built at the same time, they were just originally fitted to another loco of the same class or in some case a different class. eg some class 37's gained Deltic bogies when the Deltic's were withdrawn for example.

Absolutely! Bogies …. And therefore wheels and traction motors … were used as an interchangeable pool at both major works overhauls and depots with lift capability like Toton. This led to apparent anomalies as VB only locos might up with a set of bogies that had AB fittings. Some classes started off with different bogies types on locos in different batches - eg class 20s where there were 3 types of bogie distinguishable by the equalising beam … fluted with lightening holes, fluted without lightening holes, and plain…. They ended up being re-used indiscriminately. Yet to find a photo with different bogie types at each end on a 20 but bet there’s one out there somewhere!  And Baby Deltics used the same bogies …. 

[Flying Pig]

My old Ian Allen gives the braking force as 63 tons for a 45 against 60 tons for a 47, so the difference isn't huge.

[Richard_A]

What exactly is brake force? 

[LMS2968]

The force, usually quoted as the maximum, that the brakes can exert to stop an engine or train, expressed usually in tons or as a percentage of the weight of the engine or train. Realistically, it's the opposite of Tractive Effort, the force, usually in pounds, that an engine exerts to move the train.

[TheSignalEngineer]

5 hours ago, Phil Bullock said:

Absolutely! Bogies

When I was working in Crewe Works Signal Shop in 1968 the Tender Shop next door had been converted to do bogies instead. They had some of the bogies from the SR-designed 10201/2/3 and these were used for moving EE Type 4s around the works after their own bogies had been removed.

[The Johnster]

1 hour ago, LMS2968 said:

The force, usually quoted as the maximum, that the brakes can exert to stop an engine or train, expressed usually in tons or as a percentage of the weight of the engine or train. Realistically, it's the opposite of Tractive Effort, the force, usually in pounds, that an engine exerts to move the train.

 

And, in the same way as tractive effort can be reduced to zero when the wheels slip, brake force is reduced to zero (or less descending steep banks with heavy trains, a situation in which the train may actually accellerate) if the wheels start to skid on greasy rails.  A heavy locomotive with a lot of weight bearing down on the wheels to keep them turning while they are being retarted by the brakes has an advantage in this respect.