2 foot and 60 cm

The Ffestiniog's track gauge is generally quoted as 1' 11⅝", which is extremely close to 600 mm.
Wikipedia quotes both the WHR's and the L&B's gauges as 1' 11½" or 597 mm.
The gauge of some other railways is 2', i.e. 610 mm.

Acknowledging that any track gauge figure is nominal, affected in practice by considerations of tyre profiles, widening on curves, etc, the above figures nevertheless prompt some questions.
Are they actually correct?
How did the Ffestiniog's gauge, a nice round number in mm and not a nice round number in inches, come about?
Are the WHR and the L&B indeed ever so slightly different from the Ffestiniog, and if so why?
As the original Garratt was built for a 2' gauge railway, what if anything had to be done to its tyres for running on the WHR?

 

When first laid down the FR was quoted as 2ft gauge measured from rail centre to centre. The railway later fell in line with the convention of measuring between rail inside edge - which accounts for the rather odd gauge quoted. The width of the rail in use at the time when the change took place was obviously relevant and dictated the offset applied to the gauge quoted.

For modern standards see here :

https://www.festipedia.org.uk/wiki/Rail_gauge

There is no difference now between the FR and WHR - as you might expect. I am not aware of the specs that the L&B work to. Perhaps someone from there can chip in.

 

The only flaw in that argument is that this would require a rail head of 3/8" to make it true. It could be a logical explanation for the Penrhyn at 1'-10¾", especially if it originally started life with double flanged wheeled vehicles. The logic with that would be to specify a centre to centre dimension for wheels and rails.

 

Maybe so - but don't forget that we are talking about the early days of horse operation here when rail was only about 16lb per yard...

 

The same basic error happened in Italy which is why the NG systems were built to 950mm instead of the 1m that was the intention. Always understand the result of any measurement you make. Although the FR. L&BR, WHR, Bala, Penrhyn have different nominal gauges is there a common 'back to back' standard which would allow running on all?

 

Slightly off topic but when in Java a couple of years ago, idle curiosity led us to measure the more visible "deviations" from what was ostensibly 700mm gauge on one of the mills "main" lines and discovered a range of -10mm to + 40mm which didn't appear to bother the locos and stock most of the time. (Might have been a different matter at FR/WHR running speeds however!)

Chris

 

As I recall, when Russell ran on the FR in the 1980s - (either the 150 or the Hunslet gala) it derailed on the curve at Boston Lodge - not sure if that was a gauging issue and I am fairly sure that when FR locos have run on the VoR there has had to be some adjustment.

I do recall a discussion many years ago (30+) about whether a VoR engine could ever run on the FR. (Minffordd to TyB)

I'd assume that each line adopted whatever local quarries were using.

 

So should we try a Javanese 700mm loco on the Talyllyn?

 

The VofR was re-laid in its entirety. So is now compatible with the FR. The loco are far too wide to fit beyond Boston lodge. NGG16 bogies only fit with some bits taken off.

It actually comes down more to individual wheel profiles. You can design a profile with back to back, and tread dimensions to fit both 600mmish gauges like the FR and 2ft gauge. The ex SAR stock has quite chunky wheels which allow you to do this. Other things such as Hudson built 2ft gauge wagons have concentric rings welded on the back of the wheels to adjust the back to back for the FR.

Ex Penrhyn locos usually have the tires pushed out on the wheels slightly. They are too narrow to fit anything. Charles was apparently a total nightmare when it visited the FR.

Tim

 

I've not heard that one before. ISTR that it was difficult getting it around the sharp curve in Minffordd yard following unloading due to the limited swing of the pony trucks.
I think Russell parted company from a down passenger train near Rhiw Plas bridge - the couplings were not quite fully compatible.

 

Thanks. It was a vague memory of it derailing for some reason I had in my memory a photo of it derailed at Boston Lodge but I guess I must have imagined it.

 

The L&B gauge was originally 1 ft 11 1⁄2 in (597 mm), now being rebuilt to 600 mm (1 ft 11 5⁄8 in) so locomotive exchanges between the L&B, FR/WHR etc. are possible. In fact L&Bs Baldwin 2-4-2 LYN is visiting WHR for the Super Power weekend next month!

 

I think/recall it might have run a hot box on the rear pony truck when it first stretched its legs. The photo you remember may well have been the loco jacked up to deal with said truck rather than it being derailed?