Jacques, I know the Marklin catalogs give measurements when using the 7286 with the Marklin 72881 roundhouse.

The measurement shown in the catalog is 600mm from the turntable's centre to the rear end of the roundhouse, with a 15 degree track spacing. The doors of the roundhouse do not accommodate 7.5 degrees.

Hi Jacques,

I'm glad to hear that you are working on your new layout!

I have installed the Märklin turntable with 7.5 degree spacing, and I think it looks much better than the more usual 15 degree option.

I think the only option for a roundhouse that is designed for 7.5 degrees is the old Pola Freilassing roundhouse, marketed by Faller as model number 120218, though sadly it seems to be missing from the latest Faller catalogue. This is the one I use, and I have twelve loco stalls (though I should have built more!). Overall radius to the back of the roundhouse is 430mm (therefore 860mm diameter), according to the Faller catalogue - I haven't measured my real parts!

Turntable reliability has been perfect for me using the Märklin 7687 decoder (despite what you may have read elsewhere - I think with the recent spec turntables all the problems are sorted out), and it's a joy to watch the turntable automatically finding the right stall every time.

Control with the CS2 is great, as the functions are built in - with the CS1 it's a bit flaky unless you connect a 6040 keyboard via a 6021 to the CS1. With a 6021 or Intellibox you really need a dedicated 6040 keyboard.

Best of luck with the layout. Let us know how you get on!

Best wishes,

Nigel

hello jacques,
sounds a good decision for me to use the 7,5 degree option, most prototype turntables/roundhouse combinations have been like that, with space for a long steam loco in front of the shed. the freilassing faller roundhouse was on ebay some time ago for about 60 euros, the fleischmann roundhouse is a little bit more expensive (broken down to the cost of one stall). what you can do if you want to save some money, is to construct and build a 'skeleton' of the roundhouse only without roof and walls, this was the prototype situation after ww2 very often in germany and these sheds weren't reconstructed in full by db. i for myself plan a combination of the faller kits and these skeletons,the kits near the outer border of my layout and the skeletons more away in order to ease the manual access to the tracks in case of problems (derailments). please keep in mind that only k-track fits to the maerklin tt directly, for c or m-track you need the adapter tracks or must construct an own solution for connecting them directly to the tt. for the tracks to the roundhouse i would suggest flex track so you are not dependent on the fixed length pieces.

I thought that Faller produces a 7,5 degree roundhouse?

while my 6 main roundhouse sheds are at 15° I do have a set of 3 tracks that leave the turntable at 7,5°, 2 of which glide into some straight engine sheds, and then there are the two main entrance and exit tracks that are also at 7,5°
These can be seen at http://layout.mixmox.com/1/Engine_yard and then later with the sheds assembled in the 5th picture at http://layout.mixmox.com/1/second-roundhouse

Its all a matter of geometry, if you try to have engine shed stalls at 7,5° you may need to scratch build all your sheds and then place them quite a long way away from the turntable so that the rails are wide enough to have locos parked on adjacent tracks. This will result in a lot of empty space around the turntable.

What I suggest as a practical alternative is to do a bit of both, have some engine sheds at 15° and then some tracks (without sheds) at 7,5° on which you can store as many locos as there is space - as one typically sees around a rail preservation BW.

Running some tracks off at 7,5°and having them end up in additional (straight) sheds some way off has worked well for me in terms of space usage and aesthetics.