I have never been able to discover a picture of either the Holton Street factory nor the Keefe Avenue factory. If you know of one please do not hesitate to contact me. These photos are the closest I have discovered so far.
The original bridge was built in 1894 by the Wisconsin Bridge and Iron Co had a roadway of 26 feet and two nine-foot walks. It operated as a lift bridge. Its total length was 225 feet; its clear height above water was 70 feet, and its opening had a 66 foot clearance. Cost was $150,000.
The Holton Viaduct was built in 1926 to replace the earlier bridge completed in 1894 at a cost of $125,215.75. That bridge, although attractive, was of peculiar “folding leaf” construction, unique in the city. The bridge had to be modified to allow safe passage of street cars above. Even so, motormen had orders never to have two cars meet at the draw. According to a contemporary news article, “the dangerous inclines and curves of the Holton street viaduct have caused numerous street car and automobile accidents every year.” With the growth of automobile traffic in the early 20th century it was determined that the bridge must be replaced with a more substantial structure. By the time of its demolition, the Holton street bridge was the only remaining bridge of its kind. The 1926 Holton Street Bascule, has two pairs of bascule girders per leaf. On the Holton Street structure, the rear of each bascule girder terminates in a series of bolted castiron blocks, which jointly serve as a counterweight for the leaf.