Tag Archives: tracklaying

What’s your point?

Modelling British outline is a peculiar thing.

There are a number of constraints, historical and practical, which tempt one to compromise.

The first issue is the mismatch between track gauge and scale.

Strictly speaking, Boltorr is being built to a scale of 1:76. More accurately a strange mongrel ratio of 4mm representing 1ft – 12inches. This actually works out to 1:76.2, but this is the least of my compromises.

Still creating...
Still creating…

So, if my layout were built to scale the track gauge would be 18.83mm (4ft 8.5in @4mm/12″), right? Well,wrong. It’s going to be 16.5mm representing 4ft 2.5in. What’s gone wrong?

16.5mm was the de facto gauge for HO models (3.5mm/ft, 1:87), half of O gauge (7.00/ft 1:48 – I know…), the original continental and American compact model standard. 16.5mm is very, very close to being correct gauge for HO/1:87 scale. Unfortunately, when HO first appeared pre-WW2, standard model mechanisms wouldn’t fit in British outline stock because of the comparatively small UK loading gauge, so the larger OO was devised. The downside is that there is a tendency for UK models to look a little narrow gauge on OO track.

So you can see it’s complicated.

However, this iteration of Boltorr is being built in OO gauge. I’ve dabbled with 18.83mm gauge, now known as S4/P4, and it’s possible any follow-up could be built to that standard.

Peco GWR pattern bullhead point
Peco GWR pattern bullhead point

In the meantime, Peco have come to the rescue with their range of finescale bullhead track and points built on the Great Western pattern, which is pretty correct in every respect, other than the gauge. Since I really want something up and running, I’ve settled for that.

There’s a useful review of Peco’s new points here

Next; laying bullhead track and points, and figuring out how to control Cobalt IP switch motors.

Okay… I’m back…

Just a quick post.

Summer’s gone. I’m riding my trainer bike in the cellar (although it’s 70F/21C outside! Nearly November ffs!!!)

But it’s time to think about Boltorr again.

Autocoach for Okehampton
Autocoach for Okehampton
Pause for thought…

The bridge is almost ready. The Boltorr dam/brook crossing is pretty much together and awaiting final assembly, painting and weathering, etc. I’m thinking I’m going to assemble it as a module to maintain its integrity and drop it in then think about the water. Lots of learning and fun there…

Just awaiting a couple of bullhead points from Kernow Model Rail Centre, so track laying can commence.

There are only two (interlocked) switches on this layout, so I’m not going to DCC them. Maybe a nice signal/switch frame instead?

Plenty to think about.