(17-09-2012, 09:04 AM)Jerry1237 Wrote: You will find the layout fits on scheme very well and you will struggle with others. It is not always possible to use 4-asp where 3-asp is required.
Expect to use at least 2 different form of signalling for different areas of the layout, perhaps branch and mainline or perhaps 4 aspects around the main station on the mainline and 3 aspects further away in the plain line section.
If you decide for example 4 aspects throughout it should always work, but you'll lose marks where this is not the economically viable solution.
Also because the quantity of signals needed for a 4-aspect solution is nearly doubled, you'll waste time adding all these and thus have less time available to gain other marks. Yes the need to transition 3 to 4 and vice versa does take effort, but if you arrange things deliberately to avoid, you can expect the examiners to realise what you are doing; there will be marks available for showing you can do the activity, so if you bottle out and avoid it then you will not get those marks.
Hence you do need to do properly- take a short-cut and all you are doing is limited your ability to gain the appropriate marks.
PJW