Special Splits

[rchampine]

In some rare cases, Sanborn maps sheets indicate areas that are not to scale. In order to place buildings in the correct location, these sheets may require additional splitting that does not correspond with the typical black lines that separate maps. For these rare cases, please post the resource link here so they can be tracked.

[rchampine]

Sacramento, Calif. | 1952 | Vol. 1 p37
https://oldinsurancemaps.net/resource/8501

[rchampine]

San Francisco, Calif. | 1950 | Vol. 1
https://oldinsurancemaps.net/resource/8501
This volume and potentially all other San Francisco volumes have many sheets with right-of-ways that are not drawn to scale. Individual sheets with this issue will be tracked here when assigned within the University of Richmond georeferencing project.

[mradamcox]

It would be good to be able to add a volume-wide note about this somewhere in the interface, so people see it whenever they start working on SF content.

[nolancrees]

Des Moines, Iowa
1957 Volume 1a
At least one street, Cherry street, is drawn not-to-scale on sheets 10a-15a

[rchampine]

Richmond, Va. | 1952 | Vol. 5
https://oldinsurancemaps.net/resource/7512
This map has a driveway that's marked as not to scale because it's 100' short. Splitting to compensate.

[rchampine]

Savannah, Ga. | 1955 | Vol. 2 p133
https://oldinsurancemaps.net/resource/13945
This sheet appears to omit a half block between 38th and 39th Streets W. These is no note for this section being out of scale, but adding a extra spit to compensate for this omission resulted in better georeferencing.

[rchampine]

Phoenix, Ariz. | 1949 | Vol. 1 p41
https://oldinsurancemaps.net/resource/10474
Added additional split to compensate for S. 3rd St, which is annotated as 80' wide, but does not appear to be drawn to scale compared to other rights of way on the sheet. Separating the blocks here results in better georeferencing.

[mradamcox]

As we get closer to having a more comprehensive solution to this, and it's come up in other contexts recently, I have started a thread on the OHM/OIM forum as well: https://forum.openhistoricalmap.org/t/street-widths-not-to-scale-more-examples/389. It would be good to get some of these examples over there too.

[rchampine]

Noted! I will add some more examples soon.