Big trains question about coupling

Watched "Von Ryan's Express" last night on TV, and was surprised when it showed an Italian trainman coupling up cars: you could see the cars being pushed together, and when the buffers met, the guy ducked under one of them, grabbed the coupling hook and connected it, then quickly ducked back out.

Anyone know if this was realistic? Seems incredibly dangerous to this North Americano; but maybe that's just because of too many years of indoctrination to such things as FRA regs and working rules ...

Reply to
David Nebenzahl
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Everyday occurrence on practically every railway that used screw couplers and buffers. Probably frowned upon but men did it anyway.

-- Cheers Roger T. See the GER at: -

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Reply to
Roger T.

Actually in the "Old World" there are no "Janney Couplers" - only the buffer-and-hook-and-screw type (Russia has a central buffer coupler, but that's incompatible to everything else).

So what you did see was actually the harmless variant - I did personally observe the trainmen walking in there (between the buffers) just a few seconds before the trains actually met. While this might be against regulation, ducking under the buffers (especially when he comes from atop a platform) is acrobatic...

An effort was made in the 60ies or 70ies to develop a "european center coupler" which should have been compatible to Russia and feature air and electric connections. They wanted the gold-emitting donkey, but it should cost nothing... The result follows this line: "the hook-and-screw couplers are working well, there are few accidents and everything else costs too much"... That the manual couplers cost a lot in terms of personnel isn't in the calculation... Don't try to understand this.

Along the same lines, like I mentioned earlier, Knuckle-Couplers are exotic in European model railways... You can buy them via WWW, but you won't be compatible to your friends. They would solve a series of problems (semi-close coupling) but then, European modelers would blame the manufracturers for being non-prototypical (which the available ones aren't either) and for breaking compatibility (whatever) and not being traditional... Again, don't try to understand this, its just because it's always been done so...

Nothing against Europeans, the average person is just as nice as Americans, Asians, Russians, anyone else.

Have a nice day...

Reply to
Bernhard Agthe

60's. Knew a shunter once who happened to have his head in the wrong place when the buffers met. Didn't duck quite low enough I guess but it was 3'6" "main line" narrow gauge when all was said and done. Much facial remodeling was the result. He survived but his own mother wouldn't have recognised him after the event. His accident caused a major reshuffle, along with an altered attitude to training, in the TGR back about 40 years ago.

Krypsis

Reply to
Krypsis

Standard method (see other posts.)

However, many passenger cars now use centre couplers, some even with buffers. Most are multi-connection couplers, see photos of UK DMUs on alt.binaries.pictures.rail for examples.

British rail installed fold-down knuckle couplers on Mark 1 or 2 cars IIRC. These cars also had the screw couplers. Most Britsih DMUs have ths

HTH

Reply to
Wolf Kirchmeir

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shows several different looking Europena couplers and I don't think any of them look automatic. But I must confess, I've never seen European trains in operation either.

dlm

Reply to
Dan Merkel

I can't speak for continental Europe but in Britain the majority of passenger trains are multiple units, with automatic couplers to permit several units to be run as one train.

Some longer-distance passenger trains are loco-hauled but these are operated almost as if they were multiple units; they often have semi-permanent couplings between vehicles and are not routinely uncoupled or rearranged - only for maintenance or to deal with problems (eg to swap out a failed loco). These trains are too long to run in multiple-unit formations.

For example, the Class 365 trains which run between my home city of Cambridge and London. These are 4-car units which are very frequently coupled and uncoupled while in passenger service; many of the fast trains from London are 8 cars which run non stop to Cambridge and then divide, with the front 4 coaches carrying on to King's Lynn - and of course in the other direction, a 4-car unit from King's Lynn will be coupled up to another 4-car unit at Cambridge. This takes only a few minutes and a minimum of staff.

Wikipedia has a pretty comprehensive set of basic information about British trains at pages named like this:

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All European high speed trains (all trains >250kph anywhere?) have automatic couplers although the coupler itself is obviously covered by a panel when not in use for aerodynamic reasons. Certainly the French operate many services with two TGV sets coupled together although I don't know if they routinely uncouple/recouple at the platform, rather than in a siding or a depot, or even do it with passengers on board.

Reply to
Ian Jackson

Wait a second, automatic center couplers are seen more often, but mostly in multiple-unit-trains (to ease coupling) and on train end wagons (such as the remote cab in two-way-trains. Again, they are meant to speed up coupling passenger trains. At least in continental Europe, passenger cars still use the screw-type couplers between each other.

On the other hand you'll find permanently coupled multiple units with central couplers at the unit ends more and more often (e.g. with Jacobs bogies). They don't use any couplers internally ;-)

This may actually lead to considerable confusion because the center couplers (Scharfenberg type) are available in different types with different positioning of electrical and air connections.

In general the whole situation is quite difficult in Europe, there are national regulations (the brake pressure gauge needs a red needle in Germany and a yellow needle in Italy, e.g.), european regulations and many different established solutions. While there are different regulations in the american network also, at least the interfaces (couplers) are standard. And I do think, that the Janney couplers are a good solution (while not the best possible). The europeans missed each and every chance in history to adapt something similar... Like I said, nice people individually ;-)

Have fun!

Reply to
Bernhard Agthe

On 10/21/2008 6:14 AM Bernhard Agthe spake thus:

First of all, thanks to all who answered my question.

Now to bring up a related issue: I hate to say this, but those Yurpeen cars and locos, with their prominent buffers, just look plain funny to me. The buffers sticking out always give them, in my mind, a sort of Thomas the Tank Engine look.

Now, before you type out an angry reply to this, understand that I do realize that this is totally due to my North American railroad prejudices, and my familiarity to knuckle couplers, which I'm sure also look funny to a lot of folks outside of N.A.

In a related vein, what about those buffers? Are there any inherent advantages to either system: the Yurpeen with its separate buffers on each side, or ours where the buffer is integral with the coupler and the members connecting it to the centerbeam? Do European trains experience the same issues with coupler slack that ours do? Inquiring minds want to know ...

Reply to
David Nebenzahl

One great advantage with side buffers and screw couplings is that slack can be completely removed by tightening the screw coupling. This is normally used on European passenger trains and makes the ride much smoother than I imagine is possible with the Janney-type couplers with a lot of slack in them.

Some types of automatic centre couplers used on European DMU and EMU trains (Scharfenberg types, for instance) have no slack when coupled.

Reply to
Erik Olsen

Funny that you say that - after all Thomas the Tank Engine *IS* modeled after British prototypes (which are equipped with buffers). To Europeans Thomas looks quite correctly modeled (not just some silly cartoonish toy with buffers).

I can also relate to what you feel but in reverse. I grew up in Poland (in the 70s) and I had mini TT gauge layout (using buffered European prototype of course). When I arrived in the USA and started researching the local railroads and then modeling US railroads in N scale they all looked really funny without buffers. To me they didn't look like real trains as they were not equipped with buffers! US boxcars looked more like trucks on track than real railroad cars. At this point I got used to that look but when I look at some of my European prototype models, those buffer equipped models still look more "railroady" to me than US prototypes.

I do however remember some examples of bufferless rail vehicles from my days in Poland. All the modern trolleys used center couplings (and didn't' have buffers). Also IIRC, certain types of local commuter multi-unit trains had what looked to me like automatic center couplers (and no buffers again). Those couplings were used to couple several of permanently coupled multi-unit consists together.

Peteski

Reply to
Peter W.

The only difference between Europe and North America is that Europeans, even within the same country, mush the operational detriment, have not standardised on one coupler system.

This can and does result in a passenger m.u. failing on the mainline yet the following train cannot come up behind it and give it a push because their coupler systems and completely incompatible. They in effect, have to call a "tow truck" , in the UK known as "Thunderbirds" I gather after the 1960s/70s TV show of the same name, to come and rescue the stalled unit. Result? Delays of hours rather than minutes if both 'trains' were equipped with a standard coupler.

-- Cheers Roger T. See the GER at: -

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Reply to
Roger T.

They don't have any slack worth mentioning, actually. There buffers are in fact integral with the knuckle coupler (they are part of the coupler box.) Thus, there is little slack even in a freight train. The "issues with slack" mentioned by Dave are nothing compared to the bang-bang-bang that I used to hear when a British freight train slowed down or started up on the line a 1/2 block from where I used to live in England. OTOH, the springs in the buffers do stretch and compress as the trains move, that's prtesumably waht dave means by "slack." Hence the development of the "cushion underframe", which extends the spring travel, and thus reduces the acceleration/deceleration shocks.

On passenger cars, there is also a frame-mounted buffer above the coupler. This allows coupling with practically no slack at all. In my experience, Canadian passenger trains are as smooth as the European ones. If the track is well maintained, that is: there are stretches of track in Northern Ontario that feel a little like a roller coaster... ;-)

If there were no slack, as you call it, the ride would be exceedingly rough. The couplers in fact have an integral buffer.

HTH

Reply to
Wolf Kirchmeir

"Wolf Kirchmeir" <

Not true Wolf.

See:-

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"On mechanically sound cars, mechanical free motion or free slack between adjoining couplers can be one inch. Couplers are attached to draft gears that absorb the shock or impact. Draft gear slack is called spring slack. Spring slack on a conventional box car is about five inches. Many intermodal (piggyback) cars have shock control devises or sliding centre sills that can have fifteen inches of slack in each end.

A 100 car train of conventional cars in good mechanical condition will have

50 feet of slack. Intermodal trains and trains with cars in poor mechanical condition can have much more slack."

-- Cheers Roger T. See the GER at: -

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Reply to
Roger T.

Quite true, but what I said doesn't I think conflict with this. 1 inch of "free slack" is not worth mentioning, leastways not when you've heard and observed 4"-6" of free slack in European freight trains (plus as much or more in the buffers.) I should have been less ambiguous, I suppose, but I thought my reference to what I saw and heard in England way back when implied that the "free slack" on those freight cars was enormous compared to what we know and love in our N. American trains. ;-)

"Draft gear slack" is necessary - it's actually the buffing action, provided by the traditional side-buffers on European cars, and by integral buffers in all center couplers used today (some mine- and industrial tramway-cars excepted.) Cushion frames are designed to _increase_ that buffing action. By contrast, "free slack" is a necessary evil in knuckle couplers, it's the play within and between couplers that enables the knuckles to slide past each other and lock.

AFAIK, there should be no free slack with screw couplings, but when I observed switching in Austria a couple years ago, there was definitely more than an inch of free slack. The buffers parted 20cm or more when the loco started up the cut of cars. The coupler links were simply lifted into place (ie, "three link couplings" in effect), to save time I guess.

That's about 8ft of free slack, and up to 42ft of draft gear slack. But the train will be 5400 ft long (a 50ft car has a coupled length of about

54ft), so this slack amounts to less than 1% of total train length. Not much, really. The free slack 9the bad kind ) is less than 1/4% - very good, I'd say. Hence my "no slack worth mentioning." ;-)

It's the free slack that's the problem, since it causes unsprung shocks, which are bad, esp. for the couplers.

HTH

Reply to
Wolf Kirchmeir

Loose-coupled British goods trains are quite a special thing. Please don't think that is the norm for European freight trains.

In Denmark screw couplings have been in use on freight equipment since the very beginning in 1847 except for a series of simple open goods wagons (gondolas) that were taken over from the builders of the first Danish line.

1 inch of free slack is indeed quite much. In European freight trains with screw couplings there may be that much slack if the screw couplings are not tightened properly, and it influences running remarkably. It even increases derailment risk on rough track.

In Denmark the norm is that on freight trains screw coupling shall be tightened enough that there is no free slack. On passenger trains screw couplings shall be tightened enough that the side buffers are sligtly compressed.

Reply to
Erik Olsen

I agree. Free slack action is a serious concern to North American locomotive engineers. Freight cars will typically have at least 1 inch of slack per coupler if not more, that's about 2" per car and on a 100 car freight that's about 200 inches, or 16 feet or 4.9 metres of free slack and that's not including run in and run out of cushion underframe slack. 16 ft or 4.9 metres is nothing to sneer at when it comes to train handling. Not sure if you live in North America Wolf nor how often you get over if you don't but you need to read a bit more about our knuckle couplers. Even our North American passenger trains have some free slack action whereas, I know, European trains have none.

-- Cheers Roger T. See the GER at: -

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Reply to
Roger T.

Correction. I miss calculated.

If each car has 1" of free slack at each end, then a 100 car train has 199 coupled ends or 199 pairs of couplers coupled together which translates to (1" per coupler x 2 couplers coupled together = 2" of slack per pair of couplers) that's 199 x 2 = 398" or about 33' feet or about 10 metres.

Lots of free slack and that's not counting cushioned underframe slack.

-- Cheers Roger T. See the GER at: -

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Reply to
Roger T.

Did I say "it's always been done so"? Back in 1840 European trains started out with side buffers and coupling chains (a short piece of chains and a hook at each wagon!). Over time, they developed "three link coupling" - basically three chain links, no more, no less. Still with side buffers. Later on they found out, there is too much slack in three link couplings, but by then the chains were often attached with a pole from beside the wagons (no problem if you have loose chains). So they developed a special link (the middle one in the chain) which needed to be turned after coupling the train. This did reduce slack but did not eliminate slack. The logical next step is the screw arrangement in use today, couplers can be tightened enough to compress the buffers and to allow for (almost) no slack. This works fine and has been in use for the past fifty or hundred years. But then the guy has to go between the cars to do the coupling - we talked about that...

Now, go back to about 1900 and take the ship to North America. They were running longer and heavier trains than the Europeans (or wanted to) and they were facing the same problem. What the Americans did, they changed the system completely (not just improved it). They moved the buffer to the middle (need only one, not two, save money ;-) and put the coupler right into the new buffer (even less parts, even cheaper, save more money). The design (which is still used, though in improved form) was the most advanced one back then and serves today's railroads quite fine.

So you see, most of this has historical reasons ;-)

Now come the "modern Age" - European railroads found out that there is a serious drawback with the hook-and-screw couplers: if you're running passenger trains and want one part to stay on the main line and another part to run the side line from a certain station on, that's highly impractical (this concept has never been used much but is gaining popularity now). So they adapted center buffer couplers as well, but - being Europeans - they wanted the "BEST" design possible. The result is the "Scharfenberg" type coupler, but they did NOT design a common standard for it. There is actually only one company to produce the design, the couplers are (comparatively) complicated and thus are expensive. So they only get used in an insular fashion - the problem with broken-down trains has been mentioned.

Now, just for the fun of it, take a look at Russia. Their couplers are similar to the Janney couplers, but they use a different mechanical design. I don't want to say it's better nor worse, just different. Check it out on Wikipedia if you like. Basically the Russian type coupler was discussed for europe-wide adaption, but they wanted it "gold-plated" and with all extras for the cost of nothing. They did research a feasible design with air and electrical connections, (they even made provisions for reducing the possibility of derailments) but it was expensive. So, as you'll guess, it never got adapted...

By the way, there will always be a little slack between the wagons, but in today's railroad couplers it is reduced enough (if they get used correctly). It's a relative question, an inch is not much in a several-hundred-feet freight train, but it might be too much in an high-speed passenger train...

Now, to get back on-topic with the model railroad theme... Consider the coupling problem solved with knuckle couplers. They could even be applied to models featuring side-buffer imitations, but you'll rather find *huge* (and ugly) hook-couplers (HO) or Rapido-style (N). The wagons will sport side-buffer imitations ;-) And the hook couplers resemble hook-and-chain vaguely ;-)

Ciao...

Reply to
Bernhard Agthe

Ok, new figures accepted. But it's still not much compared to the length of the train. A 100 car train will be 5,000 feet or more. Less than 1% of train length.

So, what are the "issues with slack"? They vary, and not all of thme are bad. As I understand it, free slack can be an advantage when starting a train, as the load is incrementally increased as the slack runs out. I've read that engineers will actually reverse the engine against the train before moving forward. Is this common practice?

OTOH, on a line with many short grades, shorter than the train, slack action (both kinds) can cause problems, which are minimised by running shorter trains and running them slow. Eg, the Huron central (Sudbury - Soo, runs through my town) runs trains around 40-50 cars averaging 50ft, at about 15-20mph. They could run them up to 30-40mph, but the track is very bad. ;-)

Sprung slack has more complicated effects. A certain amount is necessary, to dampen horizontal shocks transmitted to the cars and lading. Too much can be a problem, especially when helpers are used on hilly lines on which long trains are run. Rough track can set up oscillations. Not easy to analyse, even by people who study it or work with it.

FWIW, the slack action in model trains is much more than on the prototype. I just tested it on my layout, on a 7-car train, it's about 4 scale feet (HO)!

HTH

Reply to
Wolf Kirchmeir

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