In the prototype, a Turnout is a combination of a Switch (properly called a Switch assembly as it consists of a Switch Blade and a Stock Rail bolted together, a Common Crossing (made up of a Vee with Wing rails attached) and a section joining the two called Closure Rails. We have used the same kind of terminology in the C&L range. However to keep things simple in a C&L kit the Switch Blade and innerr Closure Rails are in fact one rail, whereas in Exactoscale kits the prototype is followed exactly.

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In basic terms, an "A" type switch has a sharper radius curve than a "B" type switch, and a shorter length of planing at the tip. The planing is there to ensure that the back of the Switch Blades sits neatly against the Stock Rail. The difference that you see when you buy a set of blades is the length of this machining, the effect being that the "A" blades will produce a more sharply diverging road than "B" type blades (see last FAQ for details of the radius of the diversiong rounte for C&L kits in the various gauges).

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In theory each different angle at the Common Crossing should have a slightly different length of Switchblade, with a varying amount of rail planed away at the rear so that the blade sits neatly against the Stock Rail. In practise Rail Companies grouped Switchblades into smaller groups covering a number of closely related angles. They were given a letter from A (slow speed - sharp curve) up to sometimes G or more (very high speed gradual curved turnouts). In C&L model form we use an 'A' blade for 1:4 and 1:5 crossing angles and a 'B' blade for 1:6 upwards (except in 7mm where we offer a 'C' blade for 1:9 and above, in case someone has a garden railway with plenty of room for very long turnouts).