Shunting on the buffers & Dingham couplings - Minimum Radius for Points ?

[Combe Martin]

I'm soon (I hope) going to start building the mk2 version of a layout I've been planning for years.  It's Bailey Gate (the last station on the southern section of the S&D just a bit north of Poole).  Mk1 was in my old house (sold over a year ago) and the railway room was never big enough, though I did get the whole track layout in but much squashed.

I'm moving into my new house (with a much bigger railway room, a major criteria) in about 6 weeks, and so I can at last build the layout that I want.

 

The majority of my stock is modern RTR (good old Hornby and Bachmann, they do everything for the S&D) but I hate the the hook & bar couplings and want to use the Dingham type (there's a new version).  With these you have to shunt/propel on the buffers, and so buffer locking is a potential problem.   So, 64000 dollar question, what is the minimum radius points I need to use to avoid buffer locking ?   I was going to use Peco, either the new code 75 bullhead or code 100 flat bottom (because I have loads).  

 

The stock being shunted will be long wheel base 4 wheel vans and bogie vans, normal 4 wheel wagons and 6 wheel milk tanks.

 

Second question, what length of passenger train could I use with a Dingham coupling at the front (on a locos tender) ?.  Intermediate couplings within coach sets don't need to be Dinghams.  It's just occurred to me that total train weight could be a problem, could it ?

 

Peter.    

[davknigh]

Hi Peter,

 

Number 6 points are what I use which are equivalent to Peco large radius IIRC. I have no problems with buffer locking with either long or short wheelbase wagons or a mix of the two. The main thing is to set up your Dinghams so that the hook is behind the buffer heads because if it isn’t the hooks can catch and cause derailments. On occasion there can be problems with locomotives with a longer overhang and short wagons but this can be overcome with the use of the wider “Flippem” loops produced by Marc at :

https://pregroupingrailways.com/product/flippem-automatic-coupling-system-loops-to-be-back-fitted-to-dingham-couplings/

Note: for I suspect copyright reasons, the tail on the Flippem loop is on the opposite side from the Dingham but the couplings work the same way.

 

As for strength, I’ve had 8 Bachmann Mk1s on a Dingham loop with no problems.

 

HTH

 

David