Milepost differences - "Miles from ---"

[NW Mailing List]

The NWHS archives in Roanoke has multiple boxes of these Field notebooks dating back to the Ohio Extension, which I have used extensively  in my books on the N&W. I will provide a sample page later on today.

 

Alex Schust

 

From: NW-Mailing-List [mailto:nw-mailing-list-bounces at nwhs.org] On Behalf Of NW Mailing List
Sent: Tuesday, November 22, 2022 11:20 PM
To: N&W Mailing List
Subject: RE: Milepost differences - "Miles from ---"

 

Here is something the Gang might like to know, viz. at what point is the mileage taken for stations and named places on the railroad?  E.g. when a mile + tenths is specified for, say, Elliston or Wharncliffe, at what point do those numbers apply? 

 

Standard railroad engineering practice, in the early days, was to use the Center Line of the depot building of Tower as the mileage for that station.  In cases where there was no structure, the mileage was often given at the "P.S." (Point-of-Switch.)  Since field surveys were chained in tents of a foot from the beginning point, it was easy to come up with the decimals.  Once the depot buildings and Towers began disappearing, things became a bit more subjective. 

 

How about an Interlocking... How are mileages for those obtained?   If there were a Tower, the MP + tents for it would be used.  A perfect example of a long interlocking is Singer, between Salem and Elliston.  The distance between the opposing Home Signals is  just a tad shy of 1,000 feet, and there is no tower or depot.   At Randolph Street Interlocking in Roanoke, the interlocking limits were about 3500 feet long (before the changes of a half-dozen years ago.)  In such cases, the footage measurement is most usually made to the "central instrument house" (i.e. signal case.)  In instances of extremely long interlockings (I know of one which is just short of a mile in length,) the distance is taken from the "principle" central instrument case of the several which may be used, i.e. the one where the interlocking apparatus is interfaced with the control wires leading in. 

 

Another thing to know is that many railroads took elevations as part of their chain surveys.  The backwalls of the principal bridges, and either a window sill or one of the stone stairs of a depot building would have a bronze bolt driven in, containing a line cut across the head with a chisel.  Elevations were taken at these markers, and recorded in the field survey leather-bound notebooks.  In the case of the construction of the Transcontinental Railroad (opened in 1869,) the Army Corps of Engineers did all the chain surveys (both footages and elevations).... largely to keep the railroads from lying about how much railroad they had built` and collecting unwarranted subsidies from the Federal Treasury. 

 

The field surveyors' notebooks of many railroads often have an entry something like this on their first page:  "Field survey begun 8:30 AM, April 1, 1907, at <location>, temperature 46 degrees, light rain.  Begun at a bronze bolt driven in the west backwall of the XXX River Bridge, XX feet above mean high water.  Chained along north rail.  Survey party consisted of (name) Transit, (name) Book,  (name) and (name) Chainmen."  Sometimes the Axemen (brush cutters) would also be listed.  When a train showed up, they stopped their chaining and removed their equipment from the track, and chalk-marked the wen of the rail at the point where they had ceased working. 

 

The Valuation Maps and subsequent engineering documents all took their dimensions from these field survey books.  And I will bet the Norfolk Southern  has many feet of them on shelves in the Chief Engineer's library room, all lined up and numbered.  The railroads thought they would be here forever, and they engineered accordingly. 

 

I believe it may have been the Chief Train Dispatcher of each N&W Division who was tasked with keeping the Time Table up to date.  And no doubt, when the CTD needed a Mile Post + tenths for a Time Table or Train Sheet revision, he walked down the hall to the Division Engineer's Office and asked one of the Draughtsmen for the data. 

 

All this stuff which is now long-forgotten, and nobody even thinks about the problems, issues and practices any more. 

 

          -- abram burnett 

150 gr. Controlled Chaos Turnips 

  

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://pairlist6.pair.net/pipermail/nw-mailing-list/attachments/20221123/fa257598/attachment.htm>