Weakness & Strength of couplings: Buffer&chain; AAR and SA3

 
  Wallip Chief Commissioner

Location: Perth
Ive just returned from a holiday in Switzerland, and as a passenger, I would far perfer screw couplings. Most of the passenger services utalise 1 loco in Push / Pull mode, and the journey ride is so nice and smooth especially in Push mode. Compare the experience in Switzerland to that of Aucklands SD Sets, and its like comparing the taste of Coal and Sugar.

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  Grantham Minister for Railways

Location: I'm with stupid!
Screw couplings are under-rated, they seem to work perfectly ok everywhere in the world but here, because we apparently don't know how to stop ourselves from risking our necks to do stupid things...I bet they are more comfy from a passenger perspective than autos, and easier (and safer) to use than Shauffenburgers. Shauffenbergs don't line up very well, and shunters often stand between moving rail vehicles to feciltate or augment good coupling, maybe this is an OH&S nightmare?

M

Edited once.
  nm39 Chief Commissioner

Location: By a road taking pictures
Screw couplings are under-rated, they seem to work perfectly ok everywhere in the world but here, because we apparently don't know how to stop ourselves from risking our necks to do stupid things...I bet they are more comfy from a passenger perspective than autos, and easier (and safer) to use than Shauffenburgers. Shauffenbergs don't line up very well, and shunters often stand between moving rail vehicles to feciltate or augment good coupling, maybe this is an OH&S nightmare?

M

Edited once.
"Grantham"

Needs editing again with SpellCheck.
Scharfenberg couplings dangerous? These self aligning fully integrated couplings that are totally controlled from the cab can not possibly be dangerous unless you stand up in front of a moving train or deliberately bash yourself against them.
  Grantham Minister for Railways

Location: I'm with stupid!
Congratulations. There are meant to be as many folks between moving vehicles no matter what type of couplings are in use.

You will notice, however, that anywhere Endeavours or Explorers have to regularly couple together, there is a bar on the ground very nearby to  assist with the cab-controlled mis-alignment process.... Rolling Eyes

M
  barryc Chief Train Controller

Location: Waiting for a train to Canungra
Grantham Posted: Sun Mar 15, 2009 12:29 am

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Screw couplings are under-rated, they seem to work perfectly ok everywhere in the world but here, because we apparently don't know how to stop ourselves from risking our necks to do stupid things...I bet they are more comfy from a passenger perspective than autos, and easier (and safer) to use than Shauffenburgers. Shauffenbergs don't line up very well, and shunters often stand between moving rail vehicles to feciltate or augment good coupling, maybe this is an OH&S nightmare?

M



Screw couplings are relegated these days to loco hauled trains in Europe and some other lightly trafficked third world countries' railways.

I did my time as a shunter in an all screw coupled yard (Wollongong) and as far as I am concerned they can oxy every buffer and hook off and replace them with knuckles.

Despite what some say, you've gotta get between cars sometimes with hooks. I can guarantee I never did it because I was keen on it.
  Alco_Haulic Chief Commissioner

Location: Eating out...
Congratulations. There are meant to be as many folks between moving vehicles no matter what type of couplings are in use.

You will notice, however, that anywhere Endeavours or Explorers have to regularly couple together, there is a bar on the ground very nearby to  assist with the cab-controlled mis-alignment process.... Rolling Eyes

M
"Grantham"


Grantham you seem to be rather a fanboy of the screws. Any reason why?
  Grantham Minister for Railways

Location: I'm with stupid!
I'm just defending the poor things, everyone tells me how dangerous they are, how incapable of holding a train they are and how the buffers lock and derail the train at the slightest provocation.

Yet they're used on just about every standard gauge railway in the northern hemisphere except North America on both goods and passenger trains....it's only here (maybe only on Railpage!) that they're such an apparently bad coupling.
Rolling Eyes
M
  Alco_Haulic Chief Commissioner

Location: Eating out...
Most places agree that they are unsuited to large heavy loads. I can't think of a single heavy haul that uses chain link these days.

Personally, I can see the advantage on passenger stock for screwlinks, but in the bigger picture they are simply too man power intensive to be a credible option these days. Tightlock Janney's, and the many varieties of full auto's have their problems, but are generally much lighter on the man power needed, and can provide very small slack actions compared to the standard Janney.

Having only seen auto's in use on all trains, I have to say that watching a screw link being done up has always looked weird to me.
  sthyer Deputy Commissioner

One major drawback of the screw coupler is its inability to cope in derailments. Tightlock autos are able to withstand lateral forces and potentially prevent rollover of vehicles. Screw couplers cannot provide the same strength. I've seen photos of autos still hooked together despite the coupler shank having been torn out of the draft pocket.

This sort of action goes a long way towards holding a train together and more-or-less in a straight line, thus reducing injury. personally, I prefer the European concept of having very few collisions or derailments and good track which doesn't cause buffer lock etc. Screw couplers can operate quite well in that environment.
  Hendo Deputy Commissioner

Given how safety conscious many European countries are, especially Switzerland, I think it speaks volumes that they still use hook and screw couplings on standard gauge goods trains.
M
"Grantham"


It does not speak volumes at all, the Europeans (including the Swiss) and English made the conscious decision to stay with buffers and screw couplers as they neither had the money after the two World Wars, nor the resources to gradually convert the many thousands of loco's and wagons that cross borders every day. Look at how many years it took to convert all loco's and wagons in Australia and the long term need for transition wagons, then think of Europe and the UK (particularly pre BR) and multiply the tranisiton problem exponentially.

And at the time of transition from screw to auto couplers, Australia and North America were lucky in having essentially captive systems, either because of the states or private networks, Europe and the UK did not have this to anywhere near the same degree.

Then once you have got through that, think of the exceptionally strong rail unions and the employment issue with screw couplers versus knuckles and Scharffenburg. There was and is a very strong social need for the Eurpoeans to maintain employment, where otherwise the level may consistently be about 10 or more percent. Nevertheless the Europeans have enthusiastically adopted the Scharfenburg couplers for all passenger coaches and units.


Cheers,
Hendo
  WOB Station Staff

Technical info on various worldwide coupler types at

http://obts.wikia.com/wiki/RailCar_Couplers

WOB
  neillfarmer Chief Train Controller

Screw couplings and buffers would have to be the most dangerous method of coupling up imaginable. There is no way I would ever allow any of my children to get a job that involves working with this death trap. That should be reason enough to abandon them, let alone all the productivity advantages of auto couplers.
  Sulla1 Chief Commissioner

Screw couplings and buffers would have to be the most dangerous method of coupling up imaginable. There is no way I would ever allow any of my children to get a job that involves working with this death trap. That should be reason enough to abandon them, let alone all the productivity advantages of auto couplers.
neillfarmer

Link and pin perhaps even more so - I believe the Mossman Mill still uses link and pin, possibly one of the only rail systems left in Australia using this system. Most mill railways have moved to knuckle couplers of various types.

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