Why were the class 46 locos withdrawn so soon?

[PaxmanValenta]

The class 46's were built in the early 1960s but almost all were withdrawn by 1984 having served not much over 20 years. Was there any reliability problems and what replaced them?

 

[Peter Mugridge]

The HSTs were coming on stream at the time; we were also still in the railway downturn era - a simple cascade effect saw them made redundant as one of the least efficient and least standard fleets around.

Bear in mind that the 46s had more in common inside with the 47s than with the 45s, and we still had about 500 of the standard 47s running around at the time.

 

[RichmondCommu]

I wonder if there might have been issues with class 46 reliability as from the late 1970s they were banned west of Bristol.

 

[70014IronDuke]

It's actually a v good question.
The class 46s were actually a year or two younger than most, if not all, of the 45s.

On that basis, logic would say that they should have been chosen for converting to ETH, rather than 50 of the 45s.

But on the LM they were never considered as 'rugged' as the 45s, which had Crompton electrical gear.

I don't know how their casualty/availability records compared, however.

Once the decision was made a) to do the ETH mods on the 45s, and then b) the HSTs + 56s were introduced plus c) the loss of goods, most especially mineral traffic, I'd guess the days of the Cl 46s were numbered.

Had the mineral traffic kept up, then the 138 odd tons of the cl 46s helped their brake force rating. But with that loss, I guess they were considered both under-powered and surplus to requirements.

 

[pdeaves]

On that basis, logic would say that they should have been chosen for converting to ETH, rather than 50 of the 45s.

Conversely, as there were almost three times as many 45s as 46s, it would make sense to get rid of the smaller fleet and have better standardisation.

 

[randyrippley]

The HSTs were coming on stream at the time; we were also still in the railway downturn era - a simple cascade effect saw them made redundant as one of the least efficient and least standard fleets around.

Bear in mind that the 46s had more in common inside with the 47s than with the 45s, and we still had about 500 of the standard 47s running around at the time.

Bear in mind that by that stage BR had pretty much given up buying spare parts and were using locomotives as christmas trees.........scrapping the 46s would have been more productive in providing usable parts for both 45 and 46 than scrapping the 45.
As for banning west of Bristol, wasn't that due to removing the GW AWS for use elsewhere?

 

[Cowley]

I thought that it the 45s that were banned west of Bristol and that was in the early 1980s, more due to them breaking down too far from home (Toton?) and there not being parts available, they did occasionally go to Paignton however right up to their last year (1988).
Laira actually had an allocation of 46s in the 1970s and possibly into the early 80s? I'm not sure without looking it up.
I suppose also that with the 46s being steam heat only they would have lost work when the mk1 sleepers were withdrawn?

 

[30907]

I suppose also that with the 46s being steam heat only they would have lost work when the mk1 sleepers were withdrawn?

Though were there many sleeper workings with a 46? Midland to Glasgow obviously but other than that? Not enough to make a significant difference.

 

[Cowley]

Though were there many sleeper workings with a 46? Midland to Glasgow obviously but other than that? Not enough to make a significant difference.

I'm not sure. Did they do some of the ECML ones? I thought some were based at Gateshead.

 

[Peter Mugridge]

I'm not sure. Did they do some of the ECML ones? I thought some were based at Gateshead.

I think they did the Bristol to Birmingham leg of the North East - South West Sleeper, along with the 45s? After the Mk3 Sleepers arrived, of course, that duty was turned over to the 47s.

 

[Cowley]

I think they did the Bristol to Birmingham leg of the North East - South West Sleeper, along with the 45s? After the Mk3 Sleepers arrived, of course, that duty was turned over to the 47s.

After spending a bit of time on google I can find lots of photos of the NE/SW sleepers but no ECML ones.
The class 46s were steadily withdrawn from about 1980 which was around the time that the mk1 sleepers were being replaced. It looks like the Laira ones were some of the first to go.

 

[DarloRich]

were they not just knackered after a hard life?

 

[ainsworth74]

were they not just knackered after a hard life?

Live fast, die young?

 

[RichmondCommu]

From what I'd read the class 46's were banned west of Bristol because Laira were receiving class 46s on services from the NE in a bad state of repair. The amount of work having to be done on them before they returned north was considered unacceptable.

 

[Polarbear]

were they not just knackered after a hard life?

They were worked hard, but I'm not sure they were that knackered when they were withdrawn, other than the one that was rammed into a nuclear flask!

I suspect their relatively early withdrawal was down to a the factors outlined by other posters in the thread. Also, many (if not all) didn't have ETH which probably didn't help their cause in an era when steam heat was being rapidly phased out.

 

[ChiefPlanner]

BR had a National Traction Plan - I am sure that a diligent search in the National Archives at Kew would bring some of this up.

I went once , on duty to collect some stuff at the old archive place (now a block of luxcery flats - surprise , surprise) at Westbourne Park (the old GWR ticket printing place) - and the custodian let me have a little browse in the files , and came across intriguing files on such matters. I had to go off elsewhere , but had to go off for the day job.

 

[Clarence Yard]

They were considerably less reliable than their class 45 counterparts and when the money ran out for BR in 1980, classes 40 and 46 were the two type 4 classes that BR wanted to dispense with. By this time the introduction of both class 56 and HST sets had thrown up enough class 47 locos to enable this to start in earnest.

The 1972 ER casualty stats (taken from the 4 weekly casualty statements) gives an idea of their reliability. For the ER fleet in 1972 their class 45 locos had a miles per casualty (mpc) of 12397 where as the ER class 46 locos had an mpc of only 7421. The ER class 45 loco did an average of 80582 miles a year but the ER class 46 loco did a lesser average of 70439 miles a year. Average time between casualties was 56 days for a cl.45 and 38 days for a cl.46.

The ER class 47 fleet had an mpc of 13090, an average annual mileage of 68314 and an average time between casualties of 70 days. But their duty cycles fluctuated wildly between being thrashed on the ECML and pottering around on freight work, where the casualty threshold was much greater than 5 minutes delay. So it's not quite comparing apples with apples.

As a contrast the 14 ER Deltics did an average of 152420 miles that year with a mpc of 14616. They achieved an average time between casualties of 35 days.

 

[70014IronDuke]

...
The 1972 ER casualty stats (taken from the 4 weekly casualty statements) gives an idea of their reliability. For the ER fleet in 1972 their class 45 locos had a miles per casualty (mpc) of 12397 where as the ER class 46 locos had an mpc of only 7421. The ER class 45 loco did an average of 80582 miles a year but the ER class 46 loco did a lesser average of 70439 miles a year. Average time between casualties was 56 days for a cl.45 and 38 days for a cl.46.

Them's quite telling, nay shocking, figures for what, on paper, were the same loco, at least in terms of specification. And assuming a similar mix of duties.
It translates to the Cl 45s doing 14% more miles per annum than the 46s - that's an awful lot of extra work.

I wonder if any analysis for the differences was made? I mean, could these poorer figures for the Cl 46s be identified as caused by the Brush electrical equipment? It seems difficult to imagine. But perhaps they suffered more from flashovers and the like?

If not, you have to ask why? Did the 46s have more train heat boilers fitted proportionally (always a source of failures)? Was it inferior maintenance at specific depots?

The ER class 47 fleet had an mpc of 13090, an average annual mileage of 68314 and an average time between casualties of 70 days. But their duty cycles fluctuated wildly between being thrashed on the ECML and pottering around on freight work, where the casualty threshold was much greater than 5 minutes delay. So it's not quite comparing apples with apples.

As a contrast the 14 ER Deltics did an average of 152420 miles that year with a mpc of 14616. They achieved an average time between casualties of 35 days.

Putting the Cl 55s in there is interesting by comparison, but not really fair, since they had a special maintenance regime, and 99% of the time were on high-mileage, high-speed diagrams.

 

[70014IronDuke]

Conversely, as there were almost three times as many 45s as 46s, it would make sense to get rid of the smaller fleet and have better standardisation.

yes and no. If the Class 46s had been better locos, it would have made a good argument to ETH the lot of 'em (54?) and kept the Cl 45s as one class, but begin the withdrawal of 45s (as slightly older locos) earlier.

 

[70014IronDuke]

Though were there many sleeper workings with a 46? Midland to Glasgow obviously but other than that? Not enough to make a significant difference.

I am under the impression that the S&C was mostly 45 worked, at least up to 75 or so. That may have changed in the late 70s and 80s, I don't know for sure. I thought the 46s did find use on some ECML sleepers in the 70s at least.

 

[70014IronDuke]

were they not just knackered after a hard life?

What "hard" life? I mean, in what way was it any harder than for Cl 45s or 47s or even 40s?

If the decision was taken to ETH the Cl 45s in c 1969 (at a guess), I assume that it was already clear that the 46s were an inferior locomotive. In view of this, it is possible that the 46s were given lighter overhauls, I suppose. If so, then yes, I suppose they might have been more 'knackered' - but that would be by design, rather than by any extra-hard workings.

 

[Cowley]

Very interesting stuff. The miles per casualty figures are surprising. Especially as like 70014 says when compared to the class 47 with pretty much the same electrical equipment.

 

[Clarence Yard]

What "hard" life? I mean, in what way was it any harder than for Cl 45s or 47s or even 40s?

If the decision was taken to ETH the Cl 45s in c 1969 (at a guess), I assume that it was already clear that the 46s were an inferior locomotive. In view of this, it is possible that the 46s were given lighter overhauls, I suppose. If so, then yes, I suppose they might have been more 'knackered' - but that would be by design, rather than by any extra-hard workings.

Not in 1972. The two classes were on the same overhaul regime and both classes on ER were steam heat fitted.

 

[70014IronDuke]

Not in 1972. The two classes were on the same overhaul regime and both classes on ER were steam heat fitted.

In that case, we are comparing apples to apples (as near as one can). It's an intriguing question, and I suppose the answer might be lost in the records of ER CM&EE. (was that at York?) In 1972, it would still have been a question worth solving, if a solution could have been found, that is - although you'd have thought it would have been asked much earlier, c 1964, if the trends had been evident already. Perhaps they were just too busy fighting, er .. flashovers on Cl 46s

 

[Clarence Yard]

I have been doing a bit of digging through the 1972 ER casualty summaries and the answer to the disparity between the classes lies in a variety of component areas.

The casualties were categorised into 7 main areas (Engine, Transmission, Electrical, Air & Brake, CWA, Body and Running Gear and finally Miscellaneous). They were further split into sub categories.

The engine category is the first where there is a clear disparity. An ER cl.46 would have on average 2.10 engine related casualties that year but a ER cl.45 would only have 1.06. That's a big difference.

Getting into the sub categories, the comparison on main components is almost identical - 0.55 for a cl.46 and 0.57 for a cl.45. But when we get to the fuel system the respective comparison is 0.44 vs 0.13, lub oil system is 0.59 vs 0.16 and cooling system is 0.52 vs 0.20.

The next bit of research I have to do is go through the casualty lists and see what cause all the above they were coded to. There are a number of cause attributions such as Depot, Works, Materials etc. so they will provide a few more answers. I have my own theories, based on my own experience, but I will let the figures do the talking first.

But for the meantime let's look at some other areas of difference. The electrical equipment was another big area of disparity - 2.95 for a cl.46 vs 2.20for a cl.45. In the sub divisions there was a slight advantage in the control equipment for a cl.45 but the biggest difference was in cables - 0.66 for a cl.46vs 0.23 for a cl.45.

But the starkest difference was in the CWA (Boiler, in other words). Most ER cl.46 had the Spanner III where as the ER cl.45 all had the Stones. That showed up as an ER cl.46 loco had an average annual casualty rate for the CWA of 1.58 but for an ER cl.45 loco it was only 0.38.

 

[Cowley]

Very interesting, would love to hear your views on the differences. I'm not even going to try and speculate .

 

[Taunton]

In the days when Taunton was a significant crew change point, the Class 46 was a mainstream class which took over from the hydraulics on the NE-SW services. They were allocated to Bristol and Plymouth Laira, and I believe were the first main line diesel-electric class allocated to the latter, coming in as the Westerns disappeared. They also became the standard locos on lesser freights and engineering trains in the division. Laira never had any Class 47 allocated until much later.

They had GW pattern AWS but this disappeared in the 1970s, before they were withdrawn, as the HSTs that came along never had this so all the track installations had been changed to BR standard, which of course they also had.

The Class 45s had Crompton electrical gear, which was notably reliable (look at the Class 33), and with the surplus of large diesels with the HSTs and Class 56 coming along, the Class 46 were a minority group. An interesting supplementary question is why, in the early 1960s, did BR move away from the Crompton electrics for the last group of Peaks.

Regarding the ER Class 45/46 comparison, that's a bit misleading, as the Class 45 were all at Leeds Holbeck and the Class 46 were all at Gateshead. Different work, different depot procedures, etc, is generally more significant than any raw comparison.

 

[Clarence Yard]

BR moved away from CP because they couldn't deliver to the timescales that BR wanted. The CP works (and those of their sub contractors) had a full order book at the time.

In 1972 Holbeck had a minority allocation of class 46 locos but it wasn't a significant number. The point about different depots having different duties is well made but the procedures should be the same as all ER depots should have been working to the same book of maintenance procedures, albeit with items tailored for specific classes. The casualty system was one way of getting troublesome items included or the frequency of inspections changed.

The casualty system at the time exposed not only design failings but also depot failings. Which trades the depot was short of could get mercilessly exposed as well as the depots capacity for qualitative fault finding.

At KX DME we used the casualty analysis that I have just done to confirm how many staff we needed for fault finding or preventative routines on our own (& likely others) fleet and in those pre TOPS days making sure we planned our own fleet maintenance for the following week with enough potential repairs arising time included.

Time allowed on depot is crucial to minimising casualties and if your duty cycle doesn't allow much of it or your locos are working to depots that are only too happy to sent stuff back unrepaired "FHD", you are on to a loser.

Having said all that the ER 45/46 comparison is a valid one because it exposes not only what was going wrong with the components but also what was going on at the two depots. The latter part of the analysis is where I am heading now.

 

[Shaw S Hunter]

Something not yet mentioned; while it is true that the 46s bore a certain amount of electrical resemblance to 47s, those 47s were only the "Generators" (D1500-D1519, later 47401-47420). These 20 locos had originally been intended to be additional 46s. Had they not been fitted with ETH equipment from new they would likely have been withdrawn from service much sooner than they were and even then they were amongst the first 47/4s to be withdrawn.

 

[70014IronDuke]

Something not yet mentioned; while it is true that the 46s bore a certain amount of electrical resemblance to 47s, those 47s were only the "Generators" (D1500-D1519, later 47401-47420). These 20 locos had originally been intended to be additional 46s. Had they not been fitted with ETH equipment from new they would likely have been withdrawn from service much sooner than they were and even then they were amongst the first 47/4s to be withdrawn.

At the time of renumbering, I did wonder why they did not make the generators 47/4, and then the remaining ETH locos 47/5, because they were in many ways a v different sub-class.