Plastic Rail

There is no need to have little isolating bits as described above. If you use the live frog method of wiring, all the electrical gaps are beyond the V or K crossing.

If you have a look at my layout plan page, you can see no electrical gaps in the picture of some V crossings.

Hi Terry,

UK BH: vee nose width = 3/4"

UK FB: vee nose width = 5/8"

USA FB: vee nose width = 1/2"

Note that if you do this you should adjust the timber positions accordingly. Otherwise, if the vee nose reaches to the Fine Point (gauge-line intersection) it will be hanging in fresh air between the timbers, which looks absurd.

But not needed for P4, S7 etc., and not strictly needed for EM if wheels comply with the minimum width (2.3mm), but some are narrower.

regards,

Martin.

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only 0.2mm in 00 scale / gauge

only 0.16mm in 00 scale / gauge

As you can see from the above it will be hard to determine if your sharp nose is actually over or under scale. In practice there is no need to adjust the sleeper position, the rail can be positioned by eye to the correct looking position, the track gauges should take care of the rest.

Even with narrower wheels (for EM), wheel drop is not a problem with flangeways of around 1mm, you could go to a wheel width of 2mm without noticeable wheel drop. It's interesting that most commercial track uses flangeways around 1.4mm, with overscale blunt crossing noses and allot of models are running with 2.5mm wide wheels without derailment or noticeable wheel drop most of the time. Convention suggests 2.8mm wheel width should be the minimum for coarse scale wheels.

-- Terry Flynn

HO wagon weight and locomotive tractive effort estimates

DC control circuit diagrams

HO scale track standards

Hi Terry,

If you are modelling a prototype, "correct" is better than "correct-looking"!

For a BH 1:8 V-crossing in 4mm scale, the fine-point is 2mm in front of the blunt nose, and is shown as such on Templot templates. If you place a sharp-nose vee where a blunt one is intended, it will not line up correctly with the wing-rail knuckle and lead length. If you place it at the fine-point, it will be hanging in fresh air between the timbers. The solution is either to use a proper blunt vee, or to adjust the timber positions relative to the lead length so that a sharp vee is properly supported by a timber.

I do not agree that it is difficult to see how sharp you have made your vee. A sharp one will come to a knife-edge, and be capable of cutting flesh. In 4mm scale a correct blunt BH vee will have an easily-seen nose width of 10 thou, be much safer to handle, and be measurably shorter. For 1:8, a blunt vee is 2mm shorter than a sharp vee.

regards,

Martin.

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The relality is there are many compromises necessary to build track to practical tollerances. Even P4 and P87 are only correct looking. Finescale even is correct looking with much less precission required.

Adjusting the sleeper position will create a more obivious error than leaving the sleeper position as close to scale as the builder can achieve. All the other parts you mention should be adjusted automatically as a result of the position your track gauges hold the track in, after fixing the sharp crossing nose in position. The small deviations from scale are not noticed by the eye. Better to make the crossing nose smaller than scale than larger than scale, resulting in less wheel drop and chance of derailment.

2mm over the length of a 1 in 8 crossing is not noticeable to the eye. Just like you do not notice the difference in track gauge between EM and P4 unless they are butted end to end. The eye will not notice if the nose is 0.25mm, 0.1mm or even 0.05mm unless you are specifically looking for a difference. However excessive wheel drop is noticeable, and sharper than prototype crossing noses is a good way to improve performance of wheels through crossing V's, especially for complex trackwork involving K crossings.