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Difference in performance of class 31 & 37


Foden
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5 hours ago, russ p said:

I'm not certain early 31/4s were lower powered because the ETH was tapped from the main gen I think its still 1470bhp but when the ETH is on its shared with traction output 

The ETH on all 31/4s came from a Brush BL100-30 dual wound alternator, one winding was controlled to gave the 110v auxiliary supply and the other output gave the ETH supply (750v-1050V) . there was no tapping of the main gen for ETH supply. It wa sonly the Toffee Apples that were converted as heating units that used the main generator for this supply.

 

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10 minutes ago, 45125 said:

The ETH on all 31/4s came from a Brush BL100-30 dual wound alternator, one winding was controlled to gave the 110v auxiliary supply and the other output gave the ETH supply (750v-1050V) . there was no tapping of the main gen for ETH supply. It wa sonly the Toffee Apples that were converted as heating units that used the main generator for this supply.

 

 

 

So they would all be the same power without the ETH being on? I never noticed them being underpowered all the time regardless of the ETH being on

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On 05/12/2019 at 05:15, 45125 said:

If the ETH is turned off, the power that was been sapped by it is available for traction. It is amazing with the ETH at full load how much is sapped away, seen the traction power disappear to quite a low level when I witnessed a 31/4 on the load ban at Doncaster.

 

Lots of driver used to turn the ETH off when pulling away from some stations.

 

 

Maybe about the ETH, but my comments were mostly aimed at the raw available power from the engine.

The ETH is always going to be a drain, if it uses the same source. 

With both class 31 & 37 have ETH turned off or nonexistent, the 37 is going to have 300 more horses available to it.

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Never drove 31's but passed on 33's and 37's. The 37 was poor pulling away under a heavy loading and would cut-out if you were not super gentle with them. The view out of the cab was poor and some were fitted with some sort of device on the rad fan that squealed like a pig being slaughtered when it started up. By the time I was driving them, the cabs were draughty and the front windows leaked. The ones I got on from South Wales were in a terrible, filthy, poorly maintained state. Compared to a 33, the 37 was weaker, certainly under heavy load when trying to gain speed. If I had two 33's in multiple, they'd pul anything up any gradient.

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Ancient locos like this now only perform according to how well they've been maintained or refurbished.  Class 37s are now older than Pendennis Castle was when it went to Australia, as a bona fide historical relic (HSTs are nearly as old as Flying Scotsman was when it did its filmed 1968 nonstop run to Edinburgh, in the last days of water troughs).

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The Kings Cross/FP 31s were usually a good workhorses. Good for the suburban stuff out of Moorgate to Cambridge and the like, the Cambridge buffet expresses with 8 Mk1s were a bit of a challenge, but on the up road we had just over 101 mph coming out of Wood Green Tunnel a couple of times.

 

We had a couple overheat in hot weather with the radiator end leading out of KX, by Potters Bar the high temperature light would come on, but as the driver eased off a bit it cooled down. With the rad leading, air was blown away from the side grilles. We used them on cross-London freights, ECS to Bounds Green (ideal comfy cabs ideal for the purpose), and parcels and semi-fasts to Donny and York.

 

We struggled one Sunday with one out of KX during engineering work, 800 tons of used ballast, unfitted. Got moving, ok through Gasworks tunnel, but stalled near Holloway Carriage sidings. It was drizzling and by the time we tried to get going, got relieved. We had to put sand on the rails from our tea cans as the sanders didn't work.

 

KX men didn't sign 37s, except for a few ex Donny men. The only one I can recall going on was on the bullion train from Finsbury Park to Donny. My regular mate in 4 link Ron Birch was ex Donny.

 

The steam heat boiler was probably the most reliable of the lot.

 

KX men called the 37s "Stratford Deltics".

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On 05/12/2019 at 16:10, pheaton said:

The early 31s tapped ETH from the main generator,

 

 

Not true. 

 

ETH from Aux Generator: Classes 33, 50 and 47401-420

ETH from Aux Alternator:  Class 31/4 (all of them), 37/4, 45/1, all eth fitted 47 except 47401-420

ETH from Main Generator:  Class 55

ETH from stand alone diesel set:  Class 27/2

 

Edited by DY444
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Going a bit OT where did the ETH come from on the 40 and 37 that were experimentally fitted with it the 40 in the 60s and the 37 in the early 80s which if remember rightly was also uprated to 2000hp

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30 minutes ago, russ p said:

Going a bit OT where did the ETH come from on the 40 and 37 that were experimentally fitted with it the 40 in the 60s and the 37 in the early 80s which if remember rightly was also uprated to 2000hp

 

The class 40 was from the main generator, dunno abut the 37.

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On 04/12/2019 at 19:09, slilley said:

Certainly in the early years, Class 33 mileage was well below that of similar classes on other regions. Also their miles per casualty and availability statistics in the 1960s were not brilliant. Something that i discuss in my forthcoming Class 33 book.

Especially D6502 which did very few miles before it became a serious casualty.

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On 04/12/2019 at 19:48, Pandora said:

Did the depot Fitters ever fiddle with the 31s, achieving more than rated power by tweaking the fuel injector racks?

I would imagine that after what happened to 1562 it would have been a no-no to set engine governors and fuel racks beyond the normal ratings.

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2 hours ago, russ p said:

Going a bit OT where did the ETH come from on the 40 and 37 that were experimentally fitted with it the 40 in the 60s and the 37 in the early 80s which if remember rightly was also uprated to 2000hp

 

37292 was uprated to 2000hp for working heavy haul freight in the Motherwell area. Don't know about any ETH fitment though.

 

37/4s appeared circa 1985 with ETH of course.

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12 hours ago, DY444 said:

 

Not true. 

 

ETH from Aux Generator: Classes 33, 50 and 47401-420

 

Not quite right there

 

Class 50s had three generators, main, ETH, and auxiliary. The ETH generator was used to power the engine cooling fan which was a 1000V rated motor, the only motor that bar the traction motors, didn't have brushes bedded in after renewal due to the voltage involved.

Switching on the ETH also notched up the engine from idle.

 

Dave

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10 hours ago, dvdlcs said:

 

37292 was uprated to 2000hp for working heavy haul freight in the Motherwell area. Don't know about any ETH fitment though.

 

37/4s appeared circa 1985 with ETH of course.

 

Being trying to find out but cant find anything,  I'm sure i remember something in the early 80s about a 37 being fitted with ETH this was pre 37/4 but cant find anything about it, maybe i imagined it

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The class 31s were diagrammed to work lengthy trips with passenger trains on the ECML in the 1970s, usually in the hours of darkness of overnight trains when no witnesses present,  I had an overnight 31 Doncaster to Kings Cross, I think I was making my way to KX to ride behind a Western hauled special KX to York and return, it was the depths of winter but the steam heat Mk1 corridor stock was warm and snug in the unique manner of draught free steam heated compartment coaches,  I think the 31 was booked  was around 4 - 5  hours for the 156 miles.  Another trip was a spectacular failure, again deep snow, as the 31 entered platform 3 of Doncaster, a great flood  of coolant shot out of the side and the loco shut down immediately,  the  freezing cold weather had wrecked the radiator. In contrast to the 31 trip for the Western,  the return trip home was behind a Deltic,  waking up from my slumbers the Deltic was at a stand in either Lincoln or Gainsborough station ( rerouted for engineering possessions I assume)12 inches of snow on the platform,  had a minor panic attack, thinking  I had boarded the wrong train!

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1 hour ago, russ p said:

 

Being trying to find out but cant find anything,  I'm sure i remember something in the early 80s about a 37 being fitted with ETH this was pre 37/4 but cant find anything about it, maybe i imagined it

37292 had its engine uprated to 2000hp as a testbed because they were going to uprated the soon to be introduced 37/4s so they still had the same tractive effort as the other 37s, for whatever reason this wasnt taken forward and the 37/4s were modified at 1750hp but only an ETH index of 48 (I think) instead of the intended 66.

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15 minutes ago, royaloak said:

37292 had its engine uprated to 2000hp as a testbed because they were going to uprated the soon to be introduced 37/4s so they still had the same tractive effort as the other 37s, for whatever reason this wasnt taken forward and the 37/4s were modified at 1750hp but only an ETH index of 48 (I think) instead of the intended 66.

 

The ETH of a 37/4 is 30, about five years ago I was acting guard on a charter of 11 coaches and the generator car packed up and it was a red hot day and the loco coupled inside on the train was a 37/4 but by running AC for brief periods on different coaches managed to keep the train cool

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11 hours ago, Davexoc said:

 

Not quite right there

 

Class 50s had three generators, main, ETH, and auxiliary. The ETH generator was used to power the engine cooling fan which was a 1000V rated motor, the only motor that bar the traction motors, didn't have brushes bedded in after renewal due to the voltage involved.

Switching on the ETH also notched up the engine from idle.

 

Dave

 

True.  I was just trying to avoid breaking it down into too many categories whilst making the point that the main gen was not involved.  With hindsight perhaps it would have been better to put "ETH from an Aux Generator" :good_mini:

 

Increasing the engine rpm happened on other classes too.

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When the mighty Deltics converted from steam boiler to electric carriage heating,  what was the effect on performance? From distant memory following conversion the Deltics gained one or two quirks such as the diesel engines would not  increase engine rpm simultaneously, one engine would lead the other by several seconds of time lapse,  they were also prone to earth circuit breaker false trips if the coaches were not  to their liking

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I think the idle was set higher on one engine for ETH, and when setting off only this engine was used up to about 18mph, then the second engine joined in, but only if more than 50% power was being asked for. The change in the second engine was I believe to reduce the chances of wheel slip, particularly leaving Kings Cross, rather than anything to do with fitting of ETH.

 

The Mk2E coaches were not to be used with Deltics and generator Duffs  - not too much of a problem you would have thought, as they were mainly on the Midland Region, although the ER did acquire some Mk2e FOs before the Deltic-era ended.

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The problem with the Deltics was their performance wasn't affected too much but the ETH supply would drop sharply if power was applied too quickly. Drivers were under instruction to apply power gradually and I think that both engines were to be kept running, whereas before one engine would be used until the second was needed.

This all didn't affect the mk1 and mk2-2c so much but played havoc with the air-con mk2d etc. The ETH voltage varied so much that circuits would overload and if you were lucky, cut out

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