Different countries have their own versions of TT scale, but in the UK it is considered to be 3mm to the foot, to fit the Tri-ang Railways "TT" range introduced in the 1950s.
1958: Walkers and Holtzapffel description
T.T. GAUGE SECTION
We offer no apology for the introduction of "T.T." Gauge into our range of equipment, as, although "00" gauge has generally been found to be small enough for the majority of modellers to handle, there is no doubt that a desire for a smaller gauge exists. Even in "00" gauge the space required for a reasonably interesting layout has kept many would-be enthusiasts away from the hobby, but the introduction of a 12 mm. track gauge, with locomotives and rolling stock built to a scale of 3 mm. to the foot, enabling a double track to be laid in a diameter of 24 inches, makes possible at last a "table top" layout for the modeller who has hitherto been handicapped for lack of space. No doubt, too, this smaller gauge will attract existing "00" gauge modellers who have never quite been able to attain their ideal layout design, or run their favourite locomotive, because of unduly sharp radius curves necessitated by reasons of space restrictions. And we need hardly add that for those fortunate enough to have plenty of space the modelling of practically any section of line or terminus is a distinct possibility.
As in other gauges, the range of proprietary items available could never be sufficiently varied to cover all the requirements of enthusiasts. We shall therefore endeavour to provide such components as we feel to be necessary to enable modellers to have the same range of equipment available to them as in the larger gauges, and it is with pleasure that we are already in the position to offer products by Messrs. GEM, Hambling, Peco, S. & B., and Slater in addition to our own. The universal scale track offered gives modellers an immediate opportunity of going straight ahead with the design and construction of their layouts in this new gauge, with the certain knowledge that the components to follow will be adaptable to this track, whilst the provision of Bilteezi sheets means that the layout will not for long be without scenic effects to accurate scale dimensions.
For ourselves, we feel that the provision of a small motor unit capable of being fitted into the majority of popular locomotives, with driving wheels and axles to suit, is the most urgent need, and we believe the Romford "Terrier" motor unit listed on the following page will fill all requirements in this respect, and provide all who are keen to start this new gauge with sufficient incentive to begin construction of their layouts. We have also introduced locomotive, coach and wagon parts for the home constructor, and there are, of course, other items on the way that are not ready for inclusion in this catalogue at the time of going to press, but they will be duly advertised as they become available.
"T.T." is undoubtedly a gauge of the future, and whilst, in our opinion, the larger gauge models are, generally speaking, more impressive and easier to handle, we must emphasise to the newcomer to the hobby who is in doubt as to which gauge to adopt that the available space must be the deciding factor. It should be remembered that to run gauge "0" scale models satisfactorily the very minimum radius of curves must be 2' 10", and for" 00" gauge 2' 3", and if space does not permit these curves to be used – and how difficult this is for many of us! – then "T.T." provides the answer. A very satisfactory layout in "T.T." gauge can be planned using curves down to a radius of 1' 3", thereby enabling an interesting layout to be planned even in the most restricted space.
— , W&H, , Walkers & Holtzapffel Catalogue, , February 1958
Not to be confused with ...
... the much smaller T gauge (1:450 scale), which has a "three millimetre" rail spacing, and is three millimetre absolute, rather than three millimetres to the foot.
Media in category ‘TT scale’
The following 8 files are in this category, out of 8 total.