[PRCo] Re: Butler Harmony Map

[Stephen Titchenal]

The MapTech historical maps are the USGS 15' Topographic Maps generally done in the first quarter of the 20th Century. They were usually only done once and reissued without being updated. In a few areas they were updated. They are good enough to get you in the ball park when overlaying them and using digital elevation and current aerial photos. I have used them to identify older railroad branches and then look for the right of way on the digital elevation model and historic aerials. Depending on the year released they may not show interurbans, and in a some cases the routes through cities were not accurate. The Penn Pilot aerials were not orthorectified, so again they can get you close to the actual right of way, but camera angles and elevation have not been corrected for. Since they are actual photos, relationships between identifiable physical features and right of ways are accurate, which isn't always the case with the early topos and maps. The few early 20th Century County maps of western PA I have found are only useful for very general "ball parking" a route.

In the mid 20th Century the USGS began issuing 7.5' topos (Pittsburgh area in around 1953). They only showed trackage on private right of way, but they are much more accurate when rectified and overlayed with other maps and aerial photos. I have done this for the entire southwestern pa area. Unfortunately many interurbans were gone by this time.

For the City of Pittsburgh area I have found the Pittsburgh Department of Planning geodetic maps on the Historic Pittsburgh site to be very accurate geospatially and I have rectified and overlayed the entire set. The maps vary in year completed, and some areas are missing or never done. I am using the various Hopkins Atlases to fill in those areas and also to research other time periods. I recently picked up high resolution digital copies of the 1910 Polk and 1939 Cram maps of Pittsburgh. Both show street railways as well as railroads, although the Cram mixes street railway and bus routes without differentiating them. They are helpful in identifying locations where streets may have changed locations and names. In my research in the Cleveland area, I have found the Hopkins Atlases to be generally very accurate, but they sometimes show proposed streets and housing developments that were never built without clearly indicating that.

It is interesting to do all this research without having visited many of the Pittsburgh areas or extensive knowledge of the history of the area. I hope to do more field trips as there is nothing like visiting a site to compare what is on a map with actual observation. I am trying to refine my initial tracings and indicate the primary and secondary sources used. The most difficult primary source to find has been tracing of interurban routes through built up areas of smaller cities outside of Pittsburg as there seem to be very few (contemporary to the time) maps of those areas.

For a project unrelated to Pittsburgh, I recently began indexing more than 1700 Wheeling and Lake Erie Railroad valuation and other railroad photos by milepost. Having actual photos organized by location is another piece of the puzzle. Has anyone attempted to do this for the Pittsburgh area?  I know you can search by location in some databases, but it is useful to be able to follow a line in order using mileposts. Wayne Cole's books have been doing that for some of the interurbans and railroads in the area.

It is really something how well technology can help organize all this information, but it is time consuming to put it all together.

Stephen Titchenal
www.railsandtrails.com
www.titchenal.com
-----Original Message-----
From: pittsburgh-railways-bounce at lists.dementia.org [mailto:pittsburgh-railways-bounce at lists.dementia.org] On Behalf Of Ray
Sent: Sunday, March 27, 2011 1:32 PM
To: pittsburgh-railways at dementia.org
Subject: [PRCo] Butler Harmony Map


Thanks for all the info. Are the MapTech historic maps
accurate? I was able to trace -compare the overlays drawn on
Google with MapTech's historic maps. The Google overlays
seem pretty good with a few exceptions. I am going to try to compare
the Google overlays with Penn Pilot next.

Thanks once again

Ray