Prototype locomotives maximum speed

[jp1]

Hi,

 

I need to set up a number of 'oo' scale engines for maximum speed and I was wondering how fast the prototypes were.

 

I know a class 25 diesel managed 90 MPH and a class 08 did 15mph. Would most diesels of similar types be the same and how fast would class 101/121 DMU's be, 60 MPH?

 

What about the steam engines? Is there any guidance?

 

Speed records apart would the follwing be reasonable to assume as normal maximum operating speeds?

 

0-6-0 45-50 MPH ?

 

2-6-0/4-6-0 (and tank engines) 75 MPH ?

 

WC/BoB/MN and other 4-6-2 90 MPH?

 

Any advice welcome and thanks in advance.

[beast66606]

The speed was normally governed by the train rather than the loco - a 25 might have a top speed of 90, but on an unfitted goods it would be limited to 25mph.

[EddieB]

The speed was normally governed by the train rather than the loco - a 25 might have a top speed of 90, but on an unfitted goods it would be limited to 25mph.

 

Yes and no. All diesels and electrics used to carry a panel giving class, weight, max. speed and route availability. Obviously the lowest of the track/train/loco maximum speeds would set the limit.

[SRman]

Class 101, 121 and all the similar DMUs of that era went up to 70 mph.

 

Many main line diesels were 90 mph units but some of the older/smaller types were limited to 75 mph. Class 33 had a top speed of 85. class 24s were limited to 75, as were several similarly rated type 2s. Classes 50 and 55 were rated to 100 mph. The list of variations is quite long and what I have put here is by no means comprehensive. In a few cases, early members of the same type had a lower top speed than later members (eg class 30/31, where early ones were limited to 80 mph while later deliveries were uprated to 90).

 

(Edited to fix up some typos - I'm not very good on the mobile devices!)

[jp1]

Thanks for the info on diesels and DMU.

 

I was aware of the traffic speed limitations but I will deal with that under the computer control software I plan to use but the info on the goods train is welcomed.

 

Anyone got any ideas on the steam classes?

[LMS2968]

As far as ateam goes, there was an upper limit of 90 mph overall, but I don't recall individual engines having limits. The 9Fs were stopped from passenger work when 90 mph speeds were recorded and might have had an upper limit imposed, but I haven't heard of it.

 

0-6-0s were often used on passenger work - the L&Y often did this - and some excursions were quite long distances, so speeds of 60 mph and above would have been indulged in. Many 4-6-0s have been timed at over 90 mph: Castles, Kings, Jubilees, Scots, etc. Even humble Black Fives were clocked at that speed.

 

The limit was more often than not imposed by the engine's riding and the driver's nerve!

[PhilH]

A complete can of worms - any locos' speeds often had little to do with what they were capable of but, as pointed out the post above. what jobs they were assigned to. If you want to find out what speeds were achieved there are dozens of books and places online where passenger train runs were logged and the times and speeds recorded. Freight (goods) trains speeds depended on whether they were fitted or unfitted, for instance you wouldn't want to go down one of the banks in the Welsh valleys with 600 tons of coal in a steam engine where only that engine is fitted with a brake (apart from those pinned at the top of the bank) at much more than a crawl I would think.

 

Also goods trains often crept along from passing place to passing place where they could be overtaken by faster trains.

 

You can probably coax any light steam engine into a surprising turn of speed but it is the type of train they were on which governed how fast they went - that's where you need to base your research.

[jp1]

OK, as I said above, I get the fact that the speed in service depends on what train the engine/loco is pulling, the route it's on and the line restrictions.

 

What I wanted was a general guide to what maximum scale speed would be reasonable to set up my DCC chips to. For diesels its fairly easy as there is max speed data available. I am assuming purely for for the purposes of this exercise that this will be light engine.

 

For steam I know I can find average speeds over particular journeys but that's not what I want at this stage. I am trying to govern all my locos for max speed relative to each other at some kind of reasonable scale speed. I don't need this down to the last MPH, just something relative and reasonable.

 

I am pretty sure that running light engine a pannier tank is not going to have the same "maximum speed" capability as an A4 or a King class (it may be academic anyway as I will probably be speed limited to what the gearing and voltage will give on each model, but I would like to have some reasonable difference based upon the prototypes).

 

In that case unless the model physically limits me anyway, I intend to limit 0-6-0's to 50MPH, 2-6-0/4-6-0 to 75MPH and Pacific types to 90 MPH.

 

I am sure the pureists will take issue but I only wanted something workable for my layout that's never going to leave home.

 

Thanks for all the pointers though.

[PhilH]

Which is perfectly fine if you are going to run light engines all day long....

[jp1]

Which is perfectly fine if you are going to run light engines all day long....

 

As I said above the computer control system will take care of line restrictions limits and limits on the types of train.

[edcayton]

Would light engines be allowed to go that fast? I'd have thought the braking without a train would be poor. Something like this happened when Grand Central wanted to run shortened HST sets on the ECML and to run at 125mph.

 

Ed

[Fat Controller]

As far as ateam goes, there was an upper limit of 90 mph overall, but I don't recall individual engines having limits. The 9Fs were stopped from passenger work when 90 mph speeds were recorded and might have had an upper limit imposed, but I haven't heard of it.

 

0-6-0s were often used on passenger work - the L&Y often did this - and some excursions were quite long distances, so speeds of 60 mph and above would have been indulged in. Many 4-6-0s have been timed at over 90 mph: Castles, Kings, Jubilees, Scots, etc. Even humble Black Fives were clocked at that speed.

 

The limit was more often than not imposed by the engine's riding and the driver's nerve!

Though quite how they managed to observe speed limits when the majority of steam locos didn't have a speedometer, I wouldn't like to guess..

[mcowgill]

Light diesels are speed limited due to braking limitations.

 

The Deltics didn't seem to take much notice of what was written in the data panel, I timed one between Darlington and York at 110 mph with a full rake of Mk2s in the late 70s.

 

Martin

[asmay2002]

For steam I know I can find average speeds over particular journeys but that's not what I want at this stage. I am trying to govern all my locos for max speed relative to each other at some kind of reasonable scale speed. I don't need this down to the last MPH, just something relative and reasonable.

 

As a very rough rule of thumb for steam you could go with "diameter speed" . I.e. maximum speed in mph is equal to the diameter of the driving wheels in inches. (Yes I know modern steam locos could go faster than this on occasions e.g a 9F doing 90) but for most locos in normal service it wouldn't be far out).

[Edwin_m]

As mentioned, most diesels and electrics are not permitted to run at their maximum speed when running light, due to brake force issues. I believe more modern loco types are not restricted in this way. Diesels and electrics can and do run at their maximum speed (or even above as suggested) when hauling a reasonable length train, though probably not when climbing a severe gradient.

[ozzyo]

Hello all,

 

IIRC, in steam days a light loco was a loco and up to two brake vans, I think that these were limited to 45 M.P.H. But if it was two or more locos I'm not sure about the limit. It may have been 60 M.P.H. if the other locos had a crew on them and the locos were in steam.

 

OzzyO.

 

PS. the stationmaster may be able to help more on this!

[Rugd1022]

As mentioned, most diesels and electrics are not permitted to run at their maximum speed when running light, due to brake force issues. I believe more modern loco types are not restricted in this way. Diesels and electrics can and do run at their maximum speed (or even above as suggested) when hauling a reasonable length train, though probably not when climbing a severe gradient.

 

There are still restrictions Edwin - 60mph for light engines where the line speed is 75mph for instance.

[The Stationmaster]

Hello all,

IIRC, in steam days a light loco was a loco and up to two brake vans, I think that these were limited to 45 M.P.H. But if it was two or more locos I'm not sure about the limit. It may have been 60 M.P.H. if the other locos had a crew on them and the locos were in steam.

OzzyO.

PS. the stationmaster may be able to help more on this!

Best I can manage is as follows: (N.B. Lower speeds than those shown below could be shown in relevant sections of the Working Timetable) -

From September 1954 - speed of locos running light with the tender leading (also applicable when working a train tender first) - 45mph.

 

Maximum Permitted Speeds of Light Engines In Force From December 1958 -

Passenger and MT locos running chimney leading - 55 mph

Passenger and MT locos tender leading - 45 mph

Passenger and MT tank engines - 45 mph

Freight tender engines - 35 mph

Freight tank engines - 20 mph

in all cases subject to whatever local lower speed restrictions might apply (e.g Royal Albert Bridge 15 mph) as shown in the WTT

Where engines were coupled together the speed of the lowest would apply.

 

Engines hauled dead were restricted to 25mph irrespective of type.

 

This Instruction seems to have disappeared in the 1960 reissue of the General Appendix which suggests that it might have transferred back to WTTs from that date or have been issued only as a Departmental Instruction from then on. The only change of which I'm aware was a relaxation in 1960 to allow dead diesel and electric locos to be towed at their maximum permitted speed although this almost certainly dates from earlier.

[Alan76]

According to the late Prof Tuplin, there's evidence that a GW Saint class loco once reached something in excess of 120 mph running light on a test run between Badminton and Swindon. It sounds incredible but, according to Great Western Steam the evidence comes from times taken on the footplate and passing times logged in the train registers in the signalboxes at Hullavington and Little Somerford. It was one of those things that was not publicised at the time because it was all unofficial and highly irregular - an attempt to see just what could be done with a newly overhauled engine straight out of works. A bit off-topic, for which I apologise, but interesting isn't it?

 

Alan

[The Stationmaster]

According to the late Prof Tuplin, there's evidence that a GW Saint class loco once reached something in excess of 120 mph running light on a test run between Badminton and Swindon. It sounds incredible but, according to Great Western Steam the evidence comes from times taken on the footplate and passing times logged in the train registers in the signalboxes at Hullavington and Little Somerford. It was one of those things that was not publicised at the time because it was all unofficial and highly irregular - an attempt to see just what could be done with a newly overhauled engine straight out of works. A bit off-topic, for which I apologise, but interesting isn't it?

Alan

Sorry to stay OT but that's typical Tuplin nonsense. Swindon's light test runs were taken very slowly at first to make sure everything was bedding-in properly, I would distrust stop watches at that speed, and it would be impossible for the signalbox TRBs to confirm that speed as they booked times to the hearest whole minute and in any case might not have booked them at the precise moment the loco was passing a point which enabled that calculation to be made (at 120 mph the loco would have run from 'box to 'box in 2minutes and just under 15 seconds; but booked in whole minutes that would be recorded as 2 minutes of which 1 might have come from putting it online early and the other could have come from rounding down - all assuming that the clocks agreed precisely).

[Derekl]

To go back to the topic - the OP, I think wanted details of maximum locomotive speed in service to program the chip so that the loco would not exceed the design speed. Other costraints, such as train type and so on are to be dealt with using the controls, which seems a reasonable approach.

 

You probably know this, but Wikipedia has entries for all (most?) of the BR diesel locos and DMUs. The entries include maximum speed for each class. I assume they are accurate (the ones I have looked at make sense), but I obviously cannot vouch for that.

[jp1]

Wow,

 

thanks all. As eluded to above by Derekl the software needs to know how each engine runs and effectively creates a speed map profile (calibrated by distance measurement over time under automatic control of the software) for each engine. What I wanted to do was limit the "top speed" via programing each engines chip to something realistic before the software creates each engines profile. After the software profiles an engine it then knows (because you tell the software the weight of any train) how fast the engine can accelereate, decelerate/brake and it's attenuated top speed due to towing weight.

 

The Stationmaster and asmay2002, Mike and Andy very very helpful thanks.

 

Derekl thanks - I had overlooked wikipedia.

 

Once again I appreciate all the comments and advice.

[beast66606]

After the software profiles an engine it then knows (because you tell the software the weight of any train) how fast the engine can accelereate, decelerate/brake and it's attenuated top speed due to towing weight.

 

Don't forget the brake force of the train ... (for example unfitted would be low, fully fitted would be a lot higher) - as I said in post #2 it's really down to the type of train the loco is hauling.

[roythebus]

Light diesels are speed limited due to braking limitations.

 

The Deltics didn't seem to take much notice of what was written in the data panel, I timed one between Darlington and York at 110 mph with a full rake of Mk2s in the late 70s.

 

Martin

Slow...see my earlier thread on fastest Deltics.