TM 55-2200-001-12
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NATO UNCLASSIFIED
b.
Twin or Multiple-Track Lines. Circulation conditions are indicated for each track, e.g.:
XXXXXXXXXX A = Circulation impossible on track A.
B = Clear way on track B.
14.
These maps also show the category of each line according to the permissible weight per linear metre and the
axle loading. These categories are defined as follows:
Category
Axle loading
Weight per metre
A
16 m. tons
4.8 m. tons/metre
B1
18 m. tons
5.0 m. tons/metre
B2
18 m. tons
6.4 m. tons/metre
C2
20 m. tons
6.4 m. tons/metre
C3
20 m. tons
7.2 m. tons/metre
C4
20 m. tons
8 m. tons/metre
D.
Remarks
15.
A vehicle loaded on a NATO Category 8 wagon (the wagon taken into consideration when establishing the
envelopes) and contained within Envelope A or B /Annexes B or C) can circulate on the lines shown on the relevant
traffic map. On the other hand, a study, which can be undertaken only by the Railway Administrations, is necessary to
determine whether a vehicle loaded on a wagon other that a category 8 wagon will fit into Envelopes A and B (which
must be reduced to take account, interalia, of the difference in wheel base). Such studies are made whenever a
sketchbook sheet for a vehicle is prepared (see Part 4).
16.
National traffic maps are drawn without taking account of the existence of temporary obstacles, which will be
removed in accordance with special instructions to be issued in due course by the appropriate Railway Administrations,
so that advantage can be taken of the studies made.
17.
In the case of unforeseen obstacles, the Railway Administrations must make an actual check (and not merely a
study) to ascertain that there is sufficient room for loaded wagons to pass.
18.
Owing to the special problems arising from traffic between France and Italy within the Envelopes A and B, special
conditions have been laid down in bilateral agreements between the FS (Italian State Railways) and the SNCF (French
State Railways), to which reference should be made in connection with all transport studies involving these two nations.
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NATO UNCLASSIFIED
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