Both envelopes are vertically symmetrical and their contours above 3.370 m from the top of the rail are similar.
The inventory of the railway network lines of NATO countries which allow free passage of the
carrying wagon/load units fitting into one or the other of these envelopes resulted in the drawing up
of two maps:
one for the lines capable of accepting envelope A;
one for the lines capable of accepting envelope B.
Impracticability of Establishing a Parallel Classification of Exceptional Equipment and Flat Wagons
Suitable for Transporting them
Exceptional equipment is normally loaded on special flat wagons of categories 4 to 10 and if required
on ordinary flat wagons of categories O to 3 and on non-classified special wagons which are
designated by means of their UIC serial number or by the letters "UK".
All wagon/load units which are deemed suitable after the loading study conducted for each
exceptional equipment do not generally fit into the same envelope. As a result, the traffic conditions
could be different according to the type of wagon utilized. Since these conditions can only be
determined after considering the point of departure and arrival, the classification a "a priori" of
category (or series) of wagons best adapted to the transport of an exceptional equipment, is in most
cases not feasible. Furthermore, since the progression has not been made between categories of
special flat wagons, a parallel classification similar to the one used for ordinary equipment, which
would be workable everywhere and under all conditions, cannot be established between exceptional
equipment and special flat wagons.
Unified Sketchbook for Exceptional Military Transport. In order to make possible the designation within a
proper timescale of the flat wagons suitable for transporting exceptional equipment, the PBEIST Rail
Transport Sub-Committee has prepared a unified sketchbook which includes for each relevant equipment
the results of the loading studies as well as the static data required for the traffic studies.
This document includes a variable number of sheets. Each exceptional equipment appears on a
sheet which bears a four digit number. The numbering system has been established to prevent an
equipment used by several armies from being designated by different numbers called code numbers
(Note (8)). Each sheet provides the following information:
STANAG 2832, Part 4 - Gives all guidance about the unified sketchbook.
Change 4 BB-10