Saturday, May 30, 2009

Curved Stations

James McInerney posted a comment to my previous post about curving the station to get away from the parallel to the baseboard look.

I love the look of a curved station but have always shied away from it because of concerns about the reliability of uncoupling KDs. Uncoupling KDs is a question in itself, permanent magnets, electro-magnets, by hand, etc. that I still don't have an answer for.

I have found that the new whisker and scale head KDs are far superior in performance to the old No. 5s, however because they are so good, with 4 wheeled stock they can false uncouple when moving slowly over permanent magnet uncouplers. This is a big issue with steel axles on light 4 wheeled stock.

I only put permanent uncouplers on stub ended sidings so it's not that big an issue and can be overcome somewhat by adding weight to the wagons. This suits me as I like my loads to be heavy to give the challenge of getting up the grades with bank locos.

I am hoping to build Cassilis station yard with handlaid points as per Bylong station so curving might be the way to go, perhaps a nice broad curve will still allow the KDs to couple and uncouple, I must do some trials.


IainS said...

Modern railway practice is to eliminate curved platforms altogether as the curve can reduce guards visibility and create large gaps between the carriage body and the platform. I recall quite along discussion about the need to "straighten" Chatswood with me arguing the heritage point and property people saying there isn't any room.

So the detail police may not get you but the OHS ones will!

James McInerney said...

LOL! OHS not a problem in the era Cassilis would have been built Ian! Ray, re: uncouplers. LF solved the problem of magnetic uncouplers and four-wheel stock in two ways. Uncoupling on 'running' tracks is by undertrack permanent magnet uncouplers on a hinge, so that they are only in place when uncoupling is required. In sidings I use between the track uncouplers, but cut in half so they are shorter than a four-wheeler. Drivers have to be more accurate to uncouple in the sidings, but I demand accuracy of my drivers as a matter of course! Re: uncoupling on curves, as long as the curve is gentle, it usually isn't a problem. I have one undertrack uncoupler that is under a No.5 point, and I don't have any trouble uncoupling on the curved leg.
There is no such thing as an impossible problem, merely problems that haven't been solved yet! ;o)

IainS said...

What are the couplers - No 58's or the whisker No 148's or the 158's. I'd be interested on comments as my railway is about 1m long which doesn't really test couplers.

Ray P said...


Yes, I remember your uncoupler set ups from Lambing Flat. I am thinking about a combination of electro-uncouplers on the running lines and normal ones on the stub end sidings. The curve would be quite large if I go that way and I would probably set up a temporary curve on the baseboard before I lay the tracks to test the uncoupling and coupling.


Ray P said...


I have been slowly converting all the wagons that will be shunted to the scale head 156 and 158s. I will leave the strings of the same wagon types with the existing KD 5s to save the expense.

Locos will have either 158 for diesels and either 78 or 156 KDs for steam locos. The 78s can have the coupler box cut back by a couple of mm to get it back to the buffer beam without detracting from it's operation. See Terry Flynn's web site for more info.