In looking for web information on the Madbury pit, I ran across this website.
http://faracresfarm.com/jbvb/rr/bmrr/layout.html
Scroll down through the various lines to the Westen Route Main LIne
for some information around Dover.
Just a few comments on single tracking through Dover. The B&M
wanted to single track through Dover and abolish the gate tender
at Central Ave and the tower at Chestnut St. that controled the
gates there. The local residents were up in arms with predictions
that automatic gates would result in auto/train mishaps, especially
at Central Ave., as Chestnut St. was dead end at the Cocheco River
and did not carry that much traffic. Anyway, the B&M sweetened
up the deal by selling the Dover station to the City for $1.00. The
City studied what they could do with the three story building. One
proposal was to convert it into the Police station. Unfortunately,
there was a City Councilor that owned a bowling alley across Third
St. from the station and parking in that area was limited. He
pushed through the demolition of the fine station for a parking
lot. Even more troubling was that a few years later, he moved
his bowling alley to the outskirts of the city. Some 40 years later,
the Police Department remains in cramped quarters in the basement
of the City Hall. Another great railroad station building was gone
forever.