Coach coupling woes

[Wobblinwheel]

Using a heavy articulated locomotive of the 2-8-8-2 variety, I attempted to move a 20-coach consist from the layout to the staging yard in the next room (through a tunnel in the wall-my house, I can do what I want). I was suddenly made aware that many of the Hornby coaches near the head end of the unusually long consist ("rake?") would DERAIL as they would exit a curve. It seems the fancy "self-extending" coupling mechanism would NOT return to center if it was under heavy load. The return-spring tension was horribly inadequate to re-center the truck OR coupling!

[2e0dtoeric]

I have a *56 Diesel in EWS colours (56059 - no R number that I can see) that does exactly the same thing. More than two coaches behind it, and the swivel-sliding coupling jams to one side on a curve. So until I find a cure, it either runs light engine, or sits in the MPD, gathering dust!

[walkingthedog]

I solved this problem with my CL50.  I attached a length of stiff wire (paper clip) to the bogie and bent it up through the coupling. When the bogie swivels it takes the coupling with it. Paint it black and it's invisible. 

[Stubaggieboy]

In my humble opinion this is the worst coupling system ever. Anything coupled to any of my class 60's 31's 50's 56's derails if anymore than four coaches normally coming out of curves {not small radius]. this has been a constant annoyance to me since I purchased my first class 50 roughly 12 years ago. It is not just the loco's with this very poor design but also the lner teaks, the hawkesworth coaches that suffer from the same problem. Keeping the cam mechanim oiled helps a bit, but to me this coupling system should have been sorted out years ago.When I pay £150 plus for a loco I do not expect to have to leave it in a siding or on a shelf. I have always been loyal to Hornby as I do not own any other manufacturers loco's or rolling stock but this problem makes my blood boil

[walkingthedog]

My fix works, costs nothing, doesn't damage anything and can be removed. I always add bits to my locos so adding a bit of wire was not a problem.  

[Wobblinwheel]

I fixed about 4 of the offending coaches today. I popped the trucks (bogies?) off, and drilled a very small hole thru the center of the sliding drawbar mechanism into the underside of the coach, just ahead of the truck pivot point. I "pinned" it at that point with a straight pin (like they use in sewing, cut to about 1/4 inch) that fit tightly into the chassis, but loosely on the coupler drawbar, so it will pivot. Then, I cut-off the "ears" that cause the thing to extend when going around curves, using the spring to (still) center the coupler. Now the coupler swings, but does not extend or retract. Basically operates like a truck-mounted coupling. Once I figured it out, it took about 15 minutes per coach. Works PERFECTLY! I did not realize, until now, how that mechanism causes some erratic motion around curves! Sometimes very "jerky" as the couplers extend, then retract. I never knew exactly what was going on! Everything is VERY smooth now with the coaches I've modified. As I've converted all my stuff to Kadee knucle couplers, this modification is going to be a necessity on all stock that has this very messed-up mechanism!

[Wobblinwheel]

In my humble opinion this is the worst coupling system ever. Anything coupled to any of my class 60's 31's 50's 56's derails if anymore than four coaches normally coming out of curves {not small radius]. this has been a constant annoyance to me since I purchased my first class 50 roughly 12 years ago. It is not just the loco's with this very poor design but also the lner teaks, the hawkesworth coaches that suffer from the same problem. Keeping the cam mechanim oiled helps a bit, but to me this coupling system should have been sorted out years ago.When I pay £150 plus for a loco I do not expect to have to leave it in a siding or on a shelf. I have always been loyal to Hornby as I do not own any other manufacturers loco's or rolling stock but this problem makes my blood boil

My Hawksworth and Teaks have all been fixed now, by creating the "pivoting drawbar modification". (patents pending, teehee).....be aware, may not be advised if you have really tight turns!!

[96RAF]

I wonder if that's why on occasion my entire rake of 3 Pullmans would fall over sideways on one particular Hornby turnout (2nd rad) immediately after a long bend when behind a heavy Class 56.

[walkingthedog]

Similar to my fix then WW, let the bogie control the coupling. 

 

Fixing problems like s is one of the things I enjoy about model railways. I reckon if everything I bought just worked I'd get bored. 

[The Doc]

I've occasionally had the same problem with the mechansim on the Hornby superdetailedGresleys.  It seems very ironic to me that the older "shorty" Gresley coaches, in the Railroad range, have much simpler bogies with the old fashioned couplings and yet give closer coupling (to my eyes) than the superdetailed versions.  When gently pushed into a terminus station the corridor connectors are virtually touching, and when being pulled they are only a mm or so further apart.  What's more they never seem to derail and can manage 1st radius curves if you have them.  Why can't the newer models be re-engineered to have simpler bogie-mounted couplings that have stood the test of time?

[Wobblinwheel]

The only thing I can figure is this foul mechanism is designed for short trains and really tight curves and points. As you say, I believe truck mounted couplings would clearly solve the problem. Naw....that would be too easy, and cheaper to manufacture! However, it does appear some of Hornby's newer coaches have truck-mounted couplings, but not sprung buffers. Sprung buffers may be desirable in sharp curves with "bogie"-mounted couplings......The modification I'm doing seems to perform just like a truck-mounted coupling, and I'm finding out quicker and better ways of doing it as I go along. Some coaches work great with a simple pivot point close to the bogie pivot, and all the rest of the junk cut out and removed. No springs, no nothing. The couplings really don't have to center themselves in normal operation. Unbelievably simple, and works unbelievably well....

[Wobblinwheel]

Similar to my fix then WW, let the bogie control the coupling. 

 

Fixing problems like s is one of the things I enjoy about model railways. I reckon if everything I bought just worked I'd get bored. 

Exactly, WTD, and some coaches have a cut-out in the bogies that goes around the coupler drawbar. When the bogie turns, so does the coupler, with NO interference or bind.

[81F]

The defining factor in train length on my layout are the hidden and other loop sidings which can store up to five or six coach trains. However, I thought I would compare the pulling power of my locos. I got as far as eighteen of the corridore clerestories when things went wrong.

The shear weight of the train caused them to tip off as they went around the curve. On another the loco left the train and it's nem pocketed coupling behind!

[LCDR]

 In the UK real  trains of 20 carriages were exceptional. And on most UK model railways a train longer than 6 or 7 coaches is also unusual. It is therefore reasonable for a manufacturer to cater for what is 'normal' and not for extremes.  Even the famous National Railway Museum at York who has a huge O gauge model railway never runs passenger trains longer than 6 bogie carriages.

 

Remember we are operating on layouts where curved radii are usually rarely greater than 3 feet and more typically half that radius, which if blown up into the real world are the kind of curve that would only be found in dockyards and factories where trains of 4 wheeled wagons are hauled at 5 miles per hour by small shunting engines.  3 feet in 4mm scale equals 3.45 chains, to put this further in context  BR standard class steam locomotives  were prohibited from passing round curves tighter than 4 chains!