Rail Expansion - Instructions

The Miniature Railway Supply Co Ltd
42 Stratford Way, Boxmoor
Hemel Hempstead, Herts HP3 9AS
ENGLAND
Phone/24hr Answerphone/Fax 01442 214702
International Phone/Answerphone/Fax +44 1442 214702
www.miniaturerailwaysupply.com
e-mail: sales@miniaturerailwaysupply.com

Rail Expansion - Instructions

How to use our rail expansion data to gap your rail joints:

Assess the current rail temperature (not always the same as current ambient temperature!) and follow that colunm along the horizontal axis of the table (Table 1)

Select maximum rail temperature expected (again, which can be higher than maximum ambient temperature)

Make sure that the operating range of the rail gives a satisfactory minimum rail temperature (refer to head of table)

To obtain a wider operating range, the bolt clearance will need to be increased, this can either be acheived by increasing the length of the holes in the rail ends, or by reversing the fishbolts on one side of the rail see here

Follow maximum operating temperature down the vertical axis (Table 2)

Read off the gap dimension to allow in between the rails (at the intersection)

Example shown below, using 2lb/yd Steel rail data, rail temperature 20°C (shown in red), and maximum rail temperature of 50°C(shown in yellow), with a 0.99mm gap to be left between rails. We use drill blanks in nearest size to gap out rail

Table 1:

	Rail temperature when laid (degrees C)
Maximum Rail Temp (degrees C)	0	5	10	15	20	25	30	35	40
0	0.00	-0.17	-0.33	-0.50	-0.66	-0.83	-0.99	-1.16	-1.32
5	0.17	0.00	-0.17	-0.33	-0.50	-0.66	-0.83	-0.99	-1.16
10	0.33	0.17	0.00	-0.17	-0.33	-0.50	-0.66	-0.83	-0.99
15	0.50	0.33	0.17	0.00	-0.17	-0.33	-0.50	-0.66	-0.83
20	0.66	0.50	0.33	0.17	0.00	-0.17	-0.33	-0.50	-0.66
25	0.83	0.66	0.50	0.33	0.17	0.00	-0.17	-0.33	-0.50
30	0.99	0.83	0.66	0.50	0.33	0.17	0.00	-0.17	-0.33
35	1.16	0.99	0.83	0.66	0.50	0.33	0.17	0.00	-0.17
40	1.32	1.16	0.99	0.83	0.66	0.50	0.33	0.17	0.00
45	1.49	1.32	1.16	0.99	0.83	0.66	0.50	0.33	0.17
50	1.65	1.49	1.32	1.16	0.99	0.83	0.66	0.50	0.33
55	1.82	1.65	1.49	1.32	1.16	0.99	0.83	0.66	0.50
60	1.98	1.82	1.65	1.49	1.32	1.16	0.99	0.83	0.66
65	2.15	1.98	1.82	1.65	1.49	1.32	1.16	0.99	0.83
70	2.31	2.15	1.98	1.82	1.65	1.49	1.32	1.16	0.99
75	2.48	2.31	2.15	1.98	1.82	1.65	1.49	1.32	1.16
80	2.64	2.48	2.31	2.15	1.98	1.82	1.65	1.49	1.32
85	2.81	2.64	2.48	2.31	2.15	1.98	1.82	1.65	1.49
90	2.97	2.81	2.64	2.48	2.31	2.15	1.98	1.82	1.65
95	3.14	2.97	2.81	2.64	2.48	2.31	2.15	1.98	1.82
100	3.30	3.14	2.97	2.81	2.64	2.48	2.31	2.15	1.98

Table 2:

	Rail temperature when laid (degrees C)
Maximum Rail Temp (degrees C)	0	5	10	15	20	25	30	35	40
0	0.00	-0.17	-0.33	-0.50	-0.66	-0.83	-0.99	-1.16	-1.32
5	0.17	0.00	-0.17	-0.33	-0.50	-0.66	-0.83	-0.99	-1.16
10	0.33	0.17	0.00	-0.17	-0.33	-0.50	-0.66	-0.83	-0.99
15	0.50	0.33	0.17	0.00	-0.17	-0.33	-0.50	-0.66	-0.83
20	0.66	0.50	0.33	0.17	0.00	-0.17	-0.33	-0.50	-0.66
25	0.83	0.66	0.50	0.33	0.17	0.00	-0.17	-0.33	-0.50
30	0.99	0.83	0.66	0.50	0.33	0.17	0.00	-0.17	-0.33
35	1.16	0.99	0.83	0.66	0.50	0.33	0.17	0.00	-0.17
40	1.32	1.16	0.99	0.83	0.66	0.50	0.33	0.17	0.00
45	1.49	1.32	1.16	0.99	0.83	0.66	0.50	0.33	0.17
50	1.65	1.49	1.32	1.16	0.99	0.83	0.66	0.50	0.33
55	1.82	1.65	1.49	1.32	1.16	0.99	0.83	0.66	0.50
60	1.98	1.82	1.65	1.49	1.32	1.16	0.99	0.83	0.66
65	2.15	1.98	1.82	1.65	1.49	1.32	1.16	0.99	0.83
70	2.31	2.15	1.98	1.82	1.65	1.49	1.32	1.16	0.99
75	2.48	2.31	2.15	1.98	1.82	1.65	1.49	1.32	1.16
80	2.64	2.48	2.31	2.15	1.98	1.82	1.65	1.49	1.32
85	2.81	2.64	2.48	2.31	2.15	1.98	1.82	1.65	1.49
90	2.97	2.81	2.64	2.48	2.31	2.15	1.98	1.82	1.65
95	3.14	2.97	2.81	2.64	2.48	2.31	2.15	1.98	1.82
100	3.30	3.14	2.97	2.81	2.64	2.48	2.31	2.15	1.98

This data only applies to Miniature Railway Supply Company products

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