a. A suggested method of keeping field notes for baseline measurements is shown in Figure 3-3,
page 3-14. Complete the heading of the form in detail. The entries in columns 1 and 2 are the names of
the stations and the numbers of the tape ends. Indicate a partial tape length on a separate line, using the
number of the preceding tape end followed by the meters or the word setup. If a stake with a contact
strip is set at the half-tape point and contact is made to it, designate it as a +25 stake.
b. In columns 3 and 4, the entry of two temperatures indicates that the measurement was made with
a full 50-meter tape length; one thermometer reading indicates a half-tape length or a setup. In cases of
partial tape lengths, include explanatory notes in the remarks column to indicate the part of the tape used
in the measurement, such as 0 to 25, 25 to 50, and 0 to 10.
c. In columns 5 and 6, enter the setup and setback measurements, in meters, to 4 decimal places.
These entries, in addition to various partial tape-length measurements, include rail-movement
measurements (usually the mean of 10 per rail), and setup or setback measurements at the section ends
and at intermediate stakes used to make tape ends fall on the copper strips. Enter the number of points
of tape support in column 7. Enter a T when a tape is supported throughout. However, measurements
are seldom made with a tape supported throughout because of friction.
d. Entries in the remarks column are very important for the proper interpretation of a record. Any
unusual method of support should have an accompanying explanation in the remarks column. Note all
broken grades. Indicate the part of the tape used in a partial tape-length measurement. Enter the number
of the steel tape used opposite all measurements made using steel tape. Include remarks on any
accidents to the tapes (noting the exact point of injury) or equipment and any weather changes.
e. When the forward mark has been accurately made, move the tape ahead and repeat the process
until reaching the end of the baseline. If it is necessary to remeasure the baseline, the marks placed on
the copper strips during the second measurement should be distinguished from the first markings by a
bar across the scratch. Markings from a third measurement would have two scratches.
3-13
EN0593
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