Downtown Power Blocks I : Callahan Block

Daytonians used to have a different name for industrial lofts. Here they were called “power blocks” or “power buildings” instead of lofts. This was because these structures had their own power source, either a steam engine and belt & pulley transmission, or generator providing electric power.
As in examples in other cities power blocks were either built on spec, as sort of a vertical industrial park, or purpose-built for one company.

One of the older on-spec ones in Dayton, it seems, was the Callahan Power Building.

Apparently this structure dated from either the late 1870s or early 1880s. It was an example of a local industrialists venturing into commercial real-estate, which was a common phenomenon in 19th century Dayton. Callahan was an early foundry and machine shop, located on east 3rd (some of it is still there).

The proprietor (or his son) built commercial structures on Main, just north of Third. One was Dayton's first skyscraper.

The power building was built mid-block. The mark-up on this pic shows the expansion of National Cash Register in the building, eventually even expanding across the alley to an adjacent building, before Patterson built his own factory south of town.

As one sees from this earlier post, Delco did the same thing30 years later, but in a different “power building”.

Close inspection of Sanborn maps show the location of the chimney, boilers, engine, and freight elevator (near the large double doors for winching stuff up into the loft space), and a perhaps row of skylights running down the center of the factory. Two different views, one with up being east (1880s) the other with up being north (1890s) One can locate this building by cross referencing features visible in this pick with a Sanborn map 1. Water tower

2. Bridge across alley

3. Roof hatch

4. Skylight

5. Chamfered corner of building. This puts the building on the block just east of Main, between 2nd and 3rd …and an aerial of the same block with the power block circled (sometime in the 1920s) showing the dense building fabric:

What’s fascinating is how the block is filled-in, and the system of back alleys, which are named and called “lanes”. The original city plat had east-west lanes but made no provision for north-south alleys paralleling Main Street. These and additional north-south lanes were added in various downtown blocks.

Deep lots permitted the development of a secondary urban fabric of storage, industrial, and service buildings. Lots eventually filled as street frontage buildings incrementally expanded to the rear, eventually joining up with the back lot buildings.

One sees this throughout downtown; the interior of certain downtown blocks was a veritable Kasbah of back lot structures of various heights, little yards and courts, narrow alleys and lanes, bridges between buildings over the alleys, and so forth.