3 link couplings - were there rules about which wagon's 3 link to use?

[kitpw]

Whilst assembing a train of wagons, I find it easier to lift the link from the left hand wagon and drop it onto the draw hook of the wagon to its right (7mm scale).  However, I often find that this convention isn't followed (grandsons etc) and it doesn't make any difference to the performance of the (model)  train as far as I can tell. It did occur to me, however, that there may have been a rule about it in prototype practice which I haven't come across - a very minor point which I hesitate to raise but  it would be interesting to know!

 

 

[PeterStiles]

Are you left-handed? I find it much easier to use the links from the Right Hand Wagon?

[LMS2968]

I'm not aware of such a rule, and it wouldn't be much use for very long, given that wagons would be resorted into trains for different destinations and often reversing the direction of travel. I don't recall lifting the coupling off one wagon just to drop on the opposing coupling.

[Flood]

From the 1972 General Appendix (previous years may have had slight variations):

 

 

Some points to note:

2.4 When a non-bogie vehicle fitted with screw couplings is formed in a passenger train next to a bogie vehicle the screw coupling of the non-bogie vehicle must always be used.

 

3.3 Vehicles with Instanter couplings can be conveyed in fitted freight trains in the same way as screw-coupled vehicles, but when used in the fitted portion, the Instanter coupling must be in the short position.

When an Instanter coupling is opposed to a three-link coupling, the Instanter coupling must be used. When conveyed in Class 7 and 8 trains, the Instanter coupling must be placed in the short position.

Edited July 30, 2023 by Flood

[kitpw]

1 hour ago, PeterStiles said:

Are you left-handed?

No but I have a weaker left eye which may account for the preference! I note that the younger generations in my family are much more adept at using the 3 links than I am and display no preferences for left to right or right to left.

1 hour ago, LMS2968 said:

I don't recall lifting the coupling off one wagon just to drop on the opposing coupling.

Thanks for that, it makes sense to me but then I'm often surprised at what was covered by one rule or another and got to wondering whether I was missing something.

 

42 minutes ago, Flood said:

From the 1972 General Appendix (previous years may have had slight variations)

Thanks for posting that. I was pretty sure there were some rules about instanter and screw types and the GA confirms requirements where there are different coupling types between vehicles - the rules you draw attention to (2.4 and 3.3) certainly occur in the model and also 1.4 which requires the use of the vehicle coupling when attaching an unfitted vehicle to an engine.  This last rule is probably the most commonly encountered in model form and compliance at Swan Hill is rare!

Edited July 30, 2023 by kitpw

[brossard]

I think for the purpose of running our model trains, any coupling position that is convenient can/should be used.  Not always easy to get the link over the hook especially when there are danglies getting in the way.

 

John

[kitpw]

43 minutes ago, brossard said:

I think for the purpose of running our model trains, any coupling position that is convenient can/should be used.  Not always easy to get the link over the hook especially when there are danglies getting in the way.

True!  I've spent a bit of time recently getting the 3 links consistent for thickness of the wire in the bottom link (thin is best), thickness of the hook (again, thin is best) and making sure that the link which goes through the hook is free moving so that it doesn't hang up.  Operation has improved: swear box less often required!

 

[brossard]

42 minutes ago, kitpw said:

True!  I've spent a bit of time recently getting the 3 links consistent for thickness of the wire in the bottom link (thin is best), thickness of the hook (again, thin is best) and making sure that the link which goes through the hook is free moving so that it doesn't hang up.  Operation has improved: swear box less often required!

 

Good point, some hooks are really quite thick making it near impossible to get the link over.  Some fine tuning of these or even replacement would not go amiss.  The Dapol autocoach is one that comes to mind.  The example in our fleet has had it's couplings replaced.  I find the Dapol coupling packs to be quite good value.

 

John

[BR traction instructor]

Important to distinguish between 3 link couplings and instanter...driving a train of wagons with the former would be a very different beast to the latter (couplings in the short position) prototype wise.

 

BeRTIe

Edited July 30, 2023 by BR traction instructor

[brossard]

38 minutes ago, BR traction instructor said:

Important to distinguish between 3 link couplings and instanter...driving a train of wagons with the former would be a different beast to the latter (couplings in the short position) prototype wise.

 

BeRTIe

 

Practical considerations mean that, for my trains anyway, 3 link and instanter are treated the same way, ie instanter in the long position.  Messing about with the centre link is a non starter for me.

 

John

[kitpw]

45 minutes ago, BR traction instructor said:

driving a train of wagons with the former would be a different beast to the latter

My interest in the couplings is very much to do with how trains start, move and stop and how far that can be represented in model form so your comment pointing out the different behaviour of 3 link and instanter is exactly the sort of difference I've been thinking about although, at the moment, I don't have any instanter couplings on the layout.

 

[BR traction instructor]

Prototype wise the amount of play/slack between the buffers, multiplied by the number of wagons is very significant in the handling of a real train, especially if the wagons, or some, are loaded. Remember the guard in his brakevan at the rear, with just a handbrake and the competence of the driver to rely on. A common technique was for the guard to apply his handbrake sufficiently to keep the couplings stretched.

 

38 loaded PGA 50 ton stone hoppers with instanter couplings was a big enough challenge in the Peak District in the 1980s. It wasn't difficult to break a coupling by using poor driving technique/ignoring where the regular snatches occurred between consecutive curves/changes of gradient.

 

BeRTIe

Edited July 30, 2023 by BR traction instructor

[eldomtom2]

5 hours ago, Flood said:

From the 1972 General Appendix (previous years may have had slight variations):

 

 

Some points to note:

2.4 When a non-bogie vehicle fitted with screw couplings is formed in a passenger train next to a bogie vehicle the screw coupling of the non-bogie vehicle must always be used.

 

3.3 Vehicles with Instanter couplings can be conveyed in fitted freight trains in the same way as screw-coupled vehicles, but when used in the fitted portion, the Instanter coupling must be in the short position.

When an Instanter coupling is opposed to a three-link coupling, the Instanter coupling must be used. When conveyed in Class 7 and 8 trains, the Instanter coupling must be placed in the short position.

So am I correct in assuming that aside from some specific cases like coupling bogie to non-bogie vehicles there were no specific rules for which coupling to use when both vehicles had the same coupling?

[Wickham Green too]

Unless one of the vehicles is a locomotive - para 1.1 ( or 1.4 if the loco's only got a thee-link ! ).

[Michael Hodgson]

There were special instructions about which coupling to use when working slip coaches, though you wouldn't be coupling a wagon with 3 link to such a service.

[Wickham Green too]

... though this IS RMweb so Rule 1 might come into operation without any warning ! 😎

[Flood]

For completeness here are a couple of alterations from Supplement 2 (Dec 1976)

 

For those not used to 1970s freight train classifications:

Class 6 fully fitted express freight train (with vehicles permitted to run at 60 mph, or wagons permitted to run at less than 60 mph but with brake force not less than shown in Part 6 of the Working Manual)

Class 7 express freight train not fully fitted with brake force not less than shown in Part 6 of the Working Manual  (approx max speed 45 mph)

Class 8 freight train not fully fitted with brake force not less than shown in Part 6 of the Working Manual  (approx max speed 35 mph)

Class 9 unfitted freight train (approx max speed 25 mph)

 

Clause 2.5 reiterates the fact that there was no restriction as to which coupling was used between vehicles for Class 9 (unfitted) freight trains.

 

Edit: As model railway trains do not have continuous working braking for the stock in the train it could be argued that all model trains are Class 9, therefore any coupling can be used. 😁😉

Edited July 31, 2023 by Flood

[BR traction instructor]

8 hours ago, kitpw said:

My interest in the couplings is very much to do with how trains start, move and stop and how far that can be represented in model form so your comment pointing out the different behaviour of 3 link and instanter is exactly the sort of difference I've been thinking about although, at the moment, I don't have any instanter couplings on the layout.

 

 

Good practice with model trains fitted with 3 link/instanter/screw couplings is to stretch the couplings/take up the slack gently before accelerating. Smooth acceleration and deceleration was the norm with freight consists, there is a lot of physics going on and it isn't difficult to cause damage to rolling stock/shift loads etc and the prospect of a bruised guard approaching from his brakevan to repay his injuries at the end of a rough journey was certainly borne out in reality.

 

BeRTIe

Edited July 31, 2023 by BR traction instructor

[BR60103]

I talked about this once with a late member of The Platelayers who had been a BR driver.  He said that they would use the lighter coupling.

 

[DCB]

1 hour ago, Flood said:

Edit: As model railway trains do not have continuous working braking for the stock in the train it could be argued that all model trains are Class 9, therefore any coupling can be used. 😁😉

It's high time we had working RTR  DCC brakes in brake vans and  brake coaches.  It would make coupling up with tension locks an awful lot more realistic if the train didn't move several scale feet in the process.

 

47 minutes ago, BR traction instructor said:

Smooth acceleration and deceleration was the norm with freight consists, there is a lot of physics going on and it isn't difficult to cause damage to rolling stock/shift loads etc and the prospect of a bruised guard approaching from his brake van to repay his injuries at the end of a rough journey was certainly borne out in reality.

BeRTIe

It was a smooth start to walking speed and gradual increase in power until the whole train was moving which was required with a steam loco on a loose coupled freight.  If the loco accelerated gently the brake would do 0-10 mph in 3 feet or less. Once all the couplings are tight the driver can open up.  The overscale slop in tension lock couplings makes this taking up the slack possible in RTR 00 but generally the controllers don't and certainly the sound systems I have  come across are  totally incapable of simulating this.    Some locos also had to shut off so they could be notched up when they had lever reverse though  have seen tales of GWR drivers lifting the catch hauling the lever back as hard as they could and dropping it into which ever notch it was next to and leaving it there (and not only on freight)

The big difference between US steam and US diesel was the steam was limited by tractive effort, the ability to start trains, and Diesels by their power output and ability to haul trains at a reasonable speed as diesels produce max effort when starting and steam need to be up to speed before producing best power.
Worst combination guard wise was powerful 4 speed  diesel hydraulic on loose coupled train, if the start didn't get you the gear changes would. 

[Wickham Green too]

6 hours ago, DCB said:

It's high time we had working RTR  DCC brakes in brake vans and  brake coaches.  It would make coupling up with tension locks ...

It's high time we had working RTR three-link ( etc.) couplings so we can get rid of tension locks altogether ! 🙄

[DCB]

3 hours ago, Wickham Green too said:

It's high time we had working RTR three-link ( etc.) couplings so we can get rid of tension locks altogether ! 🙄

Its not the three links but the  23mm  tall fully functioning bloke with the shunters pole that's the problem.   

[bécasse]

It is covered by the standard "rule" that railwaymen always did the job the easiest (safe) way, as has been mentioned above that would tend to favour the lighter coupling but even the design of the buffers could have affected an individual's decision, some probably provided a better fulcrum than others.

[TheSignalEngineer]

On loose coupled trains I was told always use the coupling on the wagon sitting lowest on the springs as it reduced the risk of accidental uncoupling during braking, you couple up not couple down. 

When it came to actually doing the job I often saw shunters and guards with the pole on the buffer body of a stationary wagon, brake on, link raised on hook waiting for the moment of impact when they would twist the pole and deftly drop the link onto the hook of the  incoming wagon.

Then it was lift the brake lever and move to the new end wagon before the next cut came down and repeat.

[jim.snowdon]

Mechanically, whether the coupling is hitched up left to right, or right to left, is irrelevant. The forces are symmetrical. However, the shunter’s pole, as a tool, is designed for right handed operation. It works well when coupling the vehicle to the left of the shunter to the one on the right. The opposite way round is cackhanded.