Upcoming Games

No games to display

Full list
Add a game

Upcoming Events

No events to display

UK frieght lengths.

You are here: Home > Forum > Miscellaneous > The real thing (anything else rail-oriented) > UK frieght lengths.

Page 1 of 2

UK frieght lengths. 26/02/2014 at 16:57 #56245
RL1180
Avatar
6 posts
One thing I've been wondering while using some of the sims on here, is why the freight trains are so short on the sims. From what I've seen, most freights seem to be about 350-450m in length on most of the sims. Is that accurate to real life, or was that a design decision to make the sims more playable? The reason I'm curious is that over here in Canada, freights are never usually less then about 1800m in length(other then local switchers), with the average closer to 3000-4000m.

If the SimSig lengths are accurate, why are the trains so much shorter in the UK then in North America? Are there restriction preventing longer trains, would it jam up the system too much, is there just not enough freight to justify the longer lengths? I'm quite curious what accounts for the differences...

Log in to reply
UK frieght lengths. 26/02/2014 at 17:13 #56247
TimTamToe
Avatar
654 posts
" said:
One thing I've been wondering while using some of the sims on here, is why the freight trains are so short on the sims. From what I've seen, most freights seem to be about 350-450m in length on most of the sims. Is that accurate to real life, or was that a design decision to make the sims more playable? The reason I'm curious is that over here in Canada, freights are never usually less then about 1800m in length(other then local switchers), with the average closer to 3000-4000m.

If the SimSig lengths are accurate, why are the trains so much shorter in the UK then in North America? Are there restriction preventing longer trains, would it jam up the system too much, is there just not enough freight to justify the longer lengths? I'm quite curious what accounts for the differences...
The freight lengths on Simsig are accurate to real life. Compared to the US, Canada and also Australia the trains are a lot shorter but bear in mind the difference in the size of USA to UK and the length of time to travel the country is far less than in the states. It is more economical in the USA to have longer trains which travel 1000's of miles than more shorter ones. Do freight trains in the USA and Canada have separate tracks for a lots of their routes from passenger traffic?

As far as I know there amount of freight in the UK going by rail is on the increase.

I'm sure one of the others with more railway knowledge can explain more in detail from their personal experiences

Gareth

Last edited: 26/02/2014 at 17:15 by TimTamToe
Log in to reply
The following user said thank you: RL1180
UK frieght lengths. 26/02/2014 at 18:12 #56248
postal
Avatar
5189 posts
" said:
One thing I've been wondering while using some of the sims on here, is why the freight trains are so short on the sims. From what I've seen, most freights seem to be about 350-450m in length on most of the sims. Is that accurate to real life, or was that a design decision to make the sims more playable? The reason I'm curious is that over here in Canada, freights are never usually less then about 1800m in length(other then local switchers), with the average closer to 3000-4000m.

If the SimSig lengths are accurate, why are the trains so much shorter in the UK then in North America? Are there restriction preventing longer trains, would it jam up the system too much, is there just not enough freight to justify the longer lengths? I'm quite curious what accounts for the differences...
The current limiting factor is the infrastructure (in 2 respects that immediately come to mind). Although the amount of freight by rail is increasing, the current UK railway is essentially a passenger railway. That means that freight has to be fitted in between the passenger services and pushed out of the way when a passenger train is due. As can be seen from the loop lengths in SimSig most of the loops into which these freights can be sidelined are somewhere not far over 400m. in length which limits the length of freight train that can be allowed on the network.

The second constraint lies in the power supply. There is currently significant investment being made to extend the electrification of the UK network based on current day usage as this is seen as more ecologically friendly than diesel haulage (ss well as having economic benefits). Electrically hauled trains of overseas lengths would require upgrades in both existing and new infrastructure to supply the additional power required to move the trains.

We have similar constraints on loading gauge and so have locomotives and trains with much smaller external dimensions than those running on newer railways, all as a result of being one of the first countries to develop a railway network.

“In life, there is always someone out there, who won’t like you, for whatever reason, don’t let the insecurities in their lives affect yours.” – Rashida Rowe
Log in to reply
The following user said thank you: RL1180
UK frieght lengths. 26/02/2014 at 20:06 #56255
kbarber
Avatar
1708 posts
Online
I'd add that, in the UK, passenger traffic has tended to have quite a high priority from the very start of the industry, so freight trains have had to be operated in such a way that passenger trains could be run without delay. In steam days there used to be refuge sidings (invariably single-ended sidings trains had to reverse in to) at frequent intervals. The much greater population density here (relative to the US) meant there were plenty of signalboxes to control all these and the signalmen and/or Control were responsible for regulating freight movements so they were (hopefully) always 'inside' well clear of any passenger train.

As well as infrastructure, rolling stock had an influence too. The standard British railway wagon was a 4-wheeled (mainly wooden) box, 21 feet long over the buffers and with only handbrakes. Before WWII it was rare to find coal wagons (the most common) that carried more than about 12 tons; British Railways 'modernised' the fleet with a standard steel-built version of no less than 16 tons gross laden weight! Controlling a train of 100-odd such with nothing but the loco brakes and the handbrake in the brake van (equivalent to a caboose) was definitely an art!

The overall result was that trains tended to be much shorter, yard-to-yard runs were likewise a lot shorter, and the whole system was designed to get them moved fairly rapidly over quite short distances between refuges (or rather more slowly over permissively-worked goods lines on which, sometimes, trains would crawl pretty-much nose to tail towards their destination.

Log in to reply
The following user said thank you: RL1180
UK frieght lengths. 26/02/2014 at 20:10 #56256
RL1180
Avatar
6 posts
" said:

Do freight trains in the USA and Canada have separate tracks for a lots of their routes from passenger traffic?
You're right, this could be one of the big differences as well. With only 1 or 2 exceptions, there is very little intercity passenger rail traffic in Canada. All of the major rail mainlines around the country are owned by the freight rail companies, and the passenger trains get no special priority over the freight. In fact, when issues happen and delays are everywhere, the freight actually gets priority over the passenger trains, since the passenger trains are running on the freight railways' infrastructure. With the freight railways not having to give any sort of priority or planning to passenger moves, they are free to make the trains as long as they want.

Come to think of it, even the passenger trains over here are longer then the UK ones, which I'm sure is due to the longer distances. I've just booked a train journey for this summer, and the train I'm taking takes 1d19h to reach it's destination from the station I board at, and is usually around 26-28 cars long in the summer time (although it only runs 4 times per week in each direction...).

Log in to reply
The following user said thank you: TimTamToe
UK frieght lengths. 26/02/2014 at 20:34 #56258
Signalhunter
Avatar
177 posts
1d19h would, almost, allow you to travel from Penzance to Wick and return. Those will be the two stations furthest apart form each other.
Log in to reply
UK frieght lengths. 26/02/2014 at 20:59 #56266
RL1180
Avatar
6 posts
" said:
1d19h would, almost, allow you to travel from Penzance to Wick and return. Those will be the two stations furthest apart form each other.
I'm only getting on at the halfway point. The full journey time from Toronto to Vancouver is 3d15h, all on the same train.

Log in to reply
UK frieght lengths. 27/02/2014 at 03:58 #56279
meeko
Avatar
33 posts
" said:
Do freight trains in the USA and Canada have separate tracks for a lots of their routes from passenger traffic?
In Canada, Via Rail (a Federal Crown corporation), which operates the inter-city trains, owns bits of track here and there, but mostly run on tracks owned by CN and CPR, the 2 major freight railways, who prioritize pretty much any freight train over Via's operations.

There are also heavy rail commuter systems in the Greater Vancouver, Greater Toronto & Hamilton and Montreal areas. I'm only familiar with the GTHA system, GO Transit. It was originally directly run by the Ontario Ministry of Transportation, but is now operated by Metrolinx, a provincial Crown agency. Metrolinx has bought up a lot of the track they use in and around Toronto, but also shares track with CPR for sure, and I think they still run on some CN metal as well.

Log in to reply
The following user said thank you: TimTamToe
UK frieght lengths. 27/02/2014 at 08:13 #56281
mrtux
Avatar
19 posts
Most of what I have to say has already been mentioned.

It's a combination of the loading gauge, geographical and historical reasons as to why the UK trains are short.

The UK loading gauge is VERY small by comparison to those used in the US & Canada, and in many parts of Australia.
This means that the UK locos can't house the large engines and generators used in locos for the US, Canada & Australia.
Throw in the lower axle-loading limits, you can't make the locos weigh too much, therefore you limit the tractive effort available as well as the horsepower.
This now means that you the locos can't haul 1000m drags of wagons because the locos simply can't do it!

The geography comes in to play as well. The UK is SMALL, nothing is very far from anywhere else, so it's not necessary to make big, powerful locos capable of hauling 2~3km long freight trains.

The main historical reason that I can think if is that the when freight started to be hauled on rails in significant quantity, train-line brakes didn't exist. Only the loco and guards/brake-van had brakes, so even a 200m long freight train could get away from the crew if they weren't careful. Forget 2km!
Speeds were low, and refuge sidings and yards frequent, and most passing loops and refuge sidings have been built to accommodate the short trains.

Combine all of this, plus no doubt more things, and you can get a much better idea of why the UK runs freights in the 350~450m range, while in the US, Canada and Australia they tend to be no shorter than 1.5km long.

As an interesting point, Australia is VERY close in size to mainland USA (the first 48 states, so not including Alaska or Hawaii). The freight loading here is NOTHING like the UK or the USA, but because of the large distances involved, we tend to run 1.5km long freight trains with multiple locos up front.
Then we have 2~3km long mining trains, primarily hauling Iron Ore or Coal from mine to port. These would usually have a couple of locos in the middle of the train in addition to 2 or 3 at the front. Most of these run on dedicated lines and networks connecting the mines directly to a port. Where they run the same corridor as general freight or passenger services, they usually are shorter or have dedicated tracks.
We have comparatively little in the way of inter-city passenger movements, because there's only 20~25 million people in Australia, most of the national rail network is single track with passing loops scattered about the place. This makes it very uneconomical to run long-distance passenger services as the frequencies seen in the UK. And then there's huge competition from the airlines, being faster, cheaper and with far greater capacities.

Log in to reply
UK frieght lengths. 27/02/2014 at 10:03 #56288
kbarber
Avatar
1708 posts
Online
Another factor worth mentioning is traffic density. I don't know how many trains per day you'd see on a line carrying heavy freight traffic in Canada or the US. Here in the UK, taking the West Coast main Line as an example, there's a 4-track section as far as Rugby (80 miles from Euston) which has 12 timetable paths each way per hour on the fast lines (and probably something similar on the slows). There are crossovers every 5 - 10 miles or so, most (but not yet all) of which allow 70mph for crossover moves (the fast lines are authorised for 125mph and the slows, I think for 100 - perhaps someone who knows could confirm). Off-peak, Virgin take nine of the 12 paths with their 125mph expresses, which run fast line throughout. London Midland (the provider for intermediate stations) takes up some of the unused capacity from one crossover to the next so they can get their faster trains by their all-stations services. On the slow lines the LM services mix it with freights, a mixture of 75mph class 4 and 60mph class 6 services (the class is the first character of the train description, hence a vital piece of information for signalmen). The existence of different speeds limits maximum capacity but I don't know quite what is timetabled.

In the peaks the Virgin service ramps up to 11 trains per hour, the London Midland service also increases and I think freight is pretty much excluded altogether, allowing timetabled line capacity to be maximised.

As you can see, acceleration is an important factor for freight trains. If you put together anything much over 1200 tons it won't be able to recover quickly enough from speed restrictions or signal checks to keep out of the way of a following passenger service.

Regulating is very critical. Going back to the mid-1980s, line speeds were lower (110mph on the fast lines and 90, later upgraded to 100, on the slows); fast passenger services were booked at 110mph, stoppers at 90 and freights were as now. There was one particular box supervisor at Willesden Powerbox who was known for finding margins for freightliners (class 4) during the evening peak, though he would never do so for a class 6. Basically, he would hold a freightliner on the down goods at Wembley until a semi-fast (first stop Watford then either Hemel Hempstead or Berkhamsted but not both) went, then have it let out immediately behind. The following passenger would be an all stations (Harrow, Bushey, Watford, Kings Langley, etc). By the time it got to Harrow, it would be running on double yellows or even single yellows and might well have lost a minute. But with the station stop at Harrow (and the 'liner by now getting well into its stride) it would depart on greens and probably wouldn't see any more adverse signals - at worst a double yellow on the approach to Bushey. The 'liner would now proceed to run at 75 all the way, unless Rugby Powerbox thought they had a margin to run it 'Old Road' (via Blisworth) rather then sending it via Northampton on the 'New Line', in which case it would have to ease to 70mph for the crossovers at Hanslope.

But those day Freightliners rarely loaded to much more than 900 tons; it was only the overnight ones that would take 30 vehicles and load to 1200t.

Log in to reply
The following users said thank you: bfcmik, TimTamToe, maxand
UK frieght lengths. 27/02/2014 at 12:35 #56292
sorabain
Avatar
72 posts
On the plus side if you have a UK model railway you can run realistically long trains without needing to build the model in an aircraft hangar! hooray!
Log in to reply
UK frieght lengths. 27/02/2014 at 14:14 #56297
Danny252
Avatar
1461 posts
" said:
Another factor worth mentioning is traffic density. I don't know how many trains per day you'd see on a line carrying heavy freight traffic in Canada or the US.
A handful an hour - although when a train can take several minutes to pass by the location you're watching from, that does mean that actual track occupancy is quite high! If you end up near a large terminal or other very busy location you can get higher numbers.

Log in to reply
UK frieght lengths. 27/02/2014 at 14:43 #56299
TimTamToe
Avatar
654 posts
" said:
" said:

Do freight trains in the USA and Canada have separate tracks for a lots of their routes from passenger traffic?
You're right, this could be one of the big differences as well. With only 1 or 2 exceptions, there is very little intercity passenger rail traffic in Canada. All of the major rail mainlines around the country are owned by the freight rail companies, and the passenger trains get no special priority over the freight. In fact, when issues happen and delays are everywhere, the freight actually gets priority over the passenger trains, since the passenger trains are running on the freight railways' infrastructure. With the freight railways not having to give any sort of priority or planning to passenger moves, they are free to make the trains as long as they want.

Come to think of it, even the passenger trains over here are longer then the UK ones, which I'm sure is due to the longer distances. I've just booked a train journey for this summer, and the train I'm taking takes 1d19h to reach it's destination from the station I board at, and is usually around 26-28 cars long in the summer time (although it only runs 4 times per week in each direction...).
I thought that was the case. As you know from John's (Postal) reply, in the UK it is passenger traffic that has the priority.

Gareth

Log in to reply
UK frieght lengths. 27/02/2014 at 17:13 #56302
GeoffM
Avatar
6274 posts
In the US live cargo (ie passenger traffic) is supposed to get priority but when you've got one passenger train heading east on single track and five freights heading west, at some point something has to give otherwise the whole railway grinds to a halt. It is literally the case of slowing things down to speed things up - you stop the passenger train to let a freight or three pass, relieving congestion further up the line.

As for headways, quite often the figure of 2 miles between signals is quoted in the US. In practice it varies a lot, of course, but it's not an unreasonable average to use. I would estimate the average in the UK to be three-quarters of a mile. When BNSF built their third main track through Cajon Pass they quoted a throughput of 150 trains per day instead of 100, so we can assume 50 trains per day per track - that's a half hour headway roughly!

SimSig Boss
Log in to reply
UK frieght lengths. 27/02/2014 at 19:03 #56312
kbarber
Avatar
1708 posts
Online
" said:
When BNSF built their third main track through Cajon Pass they quoted a throughput of 150 trains per day instead of 100, so we can assume 50 trains per day per track - that's a half hour headway roughly!

In 1920 the Great Eastern Railway, with steam traction, mechanical signalling and Sykes Lock & Block working, was able to achieve a throughput of 24 trains each way per hour on one of the three pairs of tracks leaving Liverpool Street; the other two pairs continued to carry something like 15 trains each way an hour each.

Unfortunately, when Liverpool St was resignalled in 1989, the signalling was thinned out rather, the traffic having reduced considerably with the opening of the Victoria Line in 1967. Even with EMU traction I don't think Liverpool St could handle that many trains today.

Log in to reply
UK frieght lengths. 27/02/2014 at 20:02 #56313
Danny252
Avatar
1461 posts
" said:
" said:
When BNSF built their third main track through Cajon Pass they quoted a throughput of 150 trains per day instead of 100, so we can assume 50 trains per day per track - that's a half hour headway roughly!

In 1920 the Great Eastern Railway, with steam traction, mechanical signalling and Sykes Lock & Block working, was able to achieve a throughput of 24 trains each way per hour on one of the three pairs of tracks leaving Liverpool Street; the other two pairs continued to carry something like 15 trains each way an hour each.
And if you merge twenty-four 600 foot trains (engine+9) to form two 7200 foot trains, you actually get the same throughput in terms of amount of train as Cajon Pass would!

Last edited: 27/02/2014 at 20:04 by Danny252
Log in to reply
UK frieght lengths. 28/02/2014 at 05:32 #56325
maxand
Avatar
1637 posts
In Australia this is compounded by the track gauge difference between various states. New South Wales uses Standard gauge (4 ft 8 1⁄2 in) whereas we in Victoria, across the border, prefer Broad gauge (5 ft 3 in). However, interstate links are all Standard gauge.

Rail gauge in Australia (Wikipedia)

Now you can understand the reasoning behind this article which appeared recently in our local newspaper:

Freight trains may make their way through inner suburbs

Quote:
Freight trains could one day rumble through the heart of Brunswick and Coburg (Melbourne suburbs) as part of a future expansion of Victoria's freight rail network.

The Linking Melbourne Authority has revealed plans to build two extra railway tracks through Melbourne's north, directly alongside the Upfield railway line, which has in recent years experienced an apartment boom.

The new tracks are planned to run directly to the west of the existing Upfield line, which runs to Campbellfield and passes through North Melbourne, Royal Park, Brunswick, Coburg and Fawkner. Several apartment buildings have gone up in recent years on land next to the railway line, and more housing is planned near stations including Jewell and Batman.

It's not known how many railway properties along the railway line would have to be bought, as reserve exists on many stretches along the line.
...
"In consultation with Public Transport Victoria the [east-west link] design is to make allowance for the following future infrastructure: two additional standard gauge tracks on the Upfield rail line, to the west of the existing tracks, allowing for freight trains (although not double stacked container)," the authority said.

Currently the Upfield line is only used by suburban operator Metro, although it has been used by freight trains in the past.

City of Moreland chief executive Peter Brown said the council was aware of a Transport Department proposal to eventually expand the Upfield line from two tracks to four, but that there were no plans to use it for freight trains.

"All the information that council has had to date was that it wasn't to be used as a freight train route and really we would have quite a lot of concern if it was going to be used for freight trains," Mr Brown said. "You're talking about trains that sometimes are up to 500 metres to a kilometre long, and you can imagine them rattling through our suburbs."

Last edited: 28/02/2014 at 05:34 by maxand
Log in to reply
UK frieght lengths. 28/02/2014 at 09:31 #56328
kbarber
Avatar
1708 posts
Online
" said:
" said:
" said:
When BNSF built their third main track through Cajon Pass they quoted a throughput of 150 trains per day instead of 100, so we can assume 50 trains per day per track - that's a half hour headway roughly!

In 1920 the Great Eastern Railway, with steam traction, mechanical signalling and Sykes Lock & Block working, was able to achieve a throughput of 24 trains each way per hour on one of the three pairs of tracks leaving Liverpool Street; the other two pairs continued to carry something like 15 trains each way an hour each.
And if you merge twenty-four 600 foot trains (engine+9) to form two 7200 foot trains, you actually get the same throughput in terms of amount of train as Cajon Pass would!

Good thinking Danny. But 24 an hour is much more fun for the bobby

Log in to reply
UK frieght lengths. 28/02/2014 at 11:38 #56332
Danny252
Avatar
1461 posts
" said:
" said:
" said:
" said:
When BNSF built their third main track through Cajon Pass they quoted a throughput of 150 trains per day instead of 100, so we can assume 50 trains per day per track - that's a half hour headway roughly!

In 1920 the Great Eastern Railway, with steam traction, mechanical signalling and Sykes Lock & Block working, was able to achieve a throughput of 24 trains each way per hour on one of the three pairs of tracks leaving Liverpool Street; the other two pairs continued to carry something like 15 trains each way an hour each.
And if you merge twenty-four 600 foot trains (engine+9) to form two 7200 foot trains, you actually get the same throughput in terms of amount of train as Cajon Pass would!

Good thinking Danny. But 24 an hour is much more fun for the bobby ;)
I'm currently imagining the joys of staying awake long enough to check the tail lamp on the end of a 7,200ft train!

Log in to reply
UK frieght lengths. 28/02/2014 at 17:56 #56357
Finger
Avatar
220 posts
Quote:
The UK loading gauge is VERY small by comparison to those used in the US & Canada, and in many parts of Australia.
This means that the UK locos can't house the large engines and generators used in locos for the US, Canada & Australia.
Throw in the lower axle-loading limits, you can't make the locos weigh too much, therefore you limit the tractive effort available as well as the horsepower.
This now means that you the locos can't haul 1000m drags of wagons because the locos simply can't do it!

That line of reasoning is wrong - while it is certainly true that the loading gauge in UK is small, it doesn't mean UK locos lack power because of it. In fact, there are some UK diesel locomotive (eg. classes 66, 59, 70) with over 2 MW which is pretty good for a diesel loco, although not as good as contemporary American diesels, still good enough to haul a train longer than 400m. Moreover, electric locos don't need anything big and heavy to deliver high power and there are 4-6 MW electric locos even in the UK.

The real problem demonstrates itself when you try to stack more locomotives on a single train (like in America, where triples are used to haul the long trains). The locos, had there be three in front of the train, would break the screw coupling between the wagons by their combined tractive effort in no time.

As an example of a possible long train, see this article.

Log in to reply
UK frieght lengths. 28/02/2014 at 23:02 #56375
dmaze
Avatar
87 posts
" said:
In Australia this is compounded by the track gauge difference between various states.
This didn't particularly bother Brunel.

The one time I've actually been to England, I was taken to the Didcot Railway Centre. I would totally go back there and gawk having learned, for instance, that "up" and "down" aren't just arbitrary labels. But in particular, they've built some reproduction mixed-gauge track with GWR broad gauge (7' 1/4"and standard gauge (4' 8 1/2").

More topically, around Chicago, the Metra BNSF line to Aurora is worth hanging out around. There's a mix of pretty heavy commuter traffic, a small amount of Amtrak traffic, but it's also the BNSF main line towards Omaha and Denver, so you do get big coal hauls and intermodals running through there. It's the US, though, so I think it's limited to 79 mph for passenger trains and 60 mph for freight, and not electrified.

Closer to home there's very little rail freight in urban Boston (these days CSX mostly stops in Worcester, though some local traffic comes in nearer; NS rides Pan Am (ex-B&M) to Ayer, Pan Am itself mostly doesn't come closer than Lowell). The New York Metro-North system, especially the New Haven line, is pretty impressive, but there's so much commuter and Amtrak traffic that I think there are very few freight slots.

Log in to reply
UK frieght lengths. 01/03/2014 at 08:50 #56391
Forest Pines
Avatar
525 posts
" said:

This didn't particularly bother Brunel.
The evidence Brunel gave to Parliament during debates on the GWR Bill seems to show that he never really envisaged the railway system as a national network. Unless he was being disingenuous with his statements, he seemed to think the country would end up divided between completely separate regional railway companies with no mergers or through working. So therefore nobody should be concerned if he chose 7' gauge in the Thames Valley, Stephenson built his standard gauge line up to Birmingham and Locke built his down to Hampshire - they were in his mind entirely separate undertakings.

This may also explain why, when hired by two different companies which both wanted to run trains to Bristol, he designed two separate stations that were adjacent but at right-angles, with provision for through running seemingly tacked on awkwardly as an afterthought. Compare Bristol with Derby, where interchange between three railways was part of the design from the start.

Log in to reply
UK frieght lengths. 25/06/2014 at 06:32 #62010
eeldump
Avatar
19 posts
Being from the US, and working for a RR over there, I figured that it'd be good to make some belated additions to this thread.

1) Finger is right in that screw/buffers&chain couplings would have trouble with the in-train forces of longer trains. I recall reading that BR adopted rotary-type AAR couplers for their MGR coal services; is there a reason that the AAR/Janney coupler isn't more widely used in the UK for freight wagons?
2) Reading about the early BR diesels and their specs doesn't leave me with the impression that they were underpowered per se (they were at least comparable to their early US diesel contemporaries); however, multiple working seems to have gone underdeveloped in the UK rail network (several incompatible systems, and I wonder if many of them only supported 2-3 locomotives/consist, unlike the near-arbitrary MUing possible in the US where just about all the road locos in interchange service are fitted with the AAR MU system). The issue with MUing has finally mostly gone away thanks to the Yings (which are really a SD40-2 or so under the hood, and thus use the AAR MU system like their US brethren), but I suspect that nobody's dared try to MU half a dozen Yings together! (I've seen 4x4400hp consists in the US before, which would be roughly comparable to the 6x3000hp from half a dozen Yings multiply worked.)
3) Is Locotrol-type distributed power equipment even used in the UK? This is one of the main tools used in North American practice to push train lengths over 100-or-so-wagons (where especially for bulk unit trains, the in-train forces just become too colossal for even the mighty Janney coupler to handle).
4) I'm not going to even start in on passing loops, etal being too short for such monster freights, as well as the implications of that much trailing tonnage on braking distances! (At least the unfitted goods train has gone the way of the dodo...) "I put the train in full brake as soon as I saw the double yellow and I still was going 40 when I passed the home at danger!"

Log in to reply
UK frieght lengths. 25/06/2014 at 07:18 #62011
Forest Pines
Avatar
525 posts
The classic BR MGR coal wagon was the HAA four-wheel hopper. It definitely didn't have anything like an AAR coupling - from memory it used the "Instanter", a 3-link chain with a triangular middle link so it could be quickly changed between two lengths using a shunter's pole.

It's only since privatisation that coal traffic has used wagons with buckeye-type couplings, such as the HHA bogie hopper which seems to be the new standard.

Edit: this link shows an HAA and you can see the middle link of the Instanter at the left hand end - more of a T shape internally than a triangle

http://paulbartlett.zenfolio.com/brhaapost80/h262232a5

Last edited: 25/06/2014 at 07:22 by Forest Pines
Log in to reply
The following user said thank you: eeldump
UK frieght lengths. 25/06/2014 at 08:08 #62012
kbarber
Avatar
1708 posts
Online
I've an idea the rotary coupler was used in the big iron ore trains that used to run in South Wales in the '80s (I don't know the exact dates it was in use and it might have extended from the late '70s into the '90s). I believe the rotary coupler was only used within a train, with end vehicles provided that had a rotary coupler at one end and a standard screw coupling at the other.
Log in to reply