RRHX
Railroad History Story: MCRR Signal Boxes
Michigan's Internet Railroad History Museum
The picture below is of the Wasepi, Michigan crossing of the Pennsylvania Railroad GR&I Branch (which started at Fort Wayne, Indiana and ended at Mackinaw City) and the Michigan Central Railroad Airline Branch (which started at Jackson and ended at Niles). The depot on the left belonged to the PRR, but the interlocking tower on the right was the property of the Michigan Central.
You will note that
the interlocking tower has an interesting "display box", sticking out on the
MCRR side of the structure, which have numbers that face approaching trains.
The display box appears to have a chimney vent on top, suggesting that it
was lighted from within by an oil lamp.
A blow up of the box (see right photo) indicates that the top number displayed is "N69" with the bottom number displaying "225". Mark Worrall, the collector of the picture, posed the question regarding the use of the display box. Though he recalls other pictures from the Airline branch where these boxes might have been used, we could not remember a similar device being used in other locations.
Fortunately,
railroad historian Mark Dobronski came up with the answer from a Michigan
Central Railroad employee time table
No. 322, dated
November 2, 1897. Rule No. 59 on page 17 says:
"Operators at stations where the train signal boxes
are in use to show the time of departure of any train, will change the same
immediately after the departure of each train, giving the correct time such
train passed, and are required to see that signal boxes are kept clear from
snow and ice, and that the figures are clearly shown. Trains will be
designated as follows: Regular trains by [N.] Specials by [S.] Extra by
[X.] Engineers and Conductors are required to report to their
Division Supt. any cases which may come to their knowledge where the time of
a preceding train is not correctly or plainly shown, and also all cases
where signal boxes are not lighted after dark. The time of regular Freights
or extra train must not be taken until Way-Car passes the Telegraph office."
So, this appears to solve the mystery.
These boxes were used to let trains know who was ahead and how long it had
been since the last departure. This apparently gave following
engineers some form of comfort that the way ahead was clear. We're not
sure whether these were used anywhere except for the MCRR's Airline branch.