Rock colors

NW Mailing List nw-mailing-list at
Tue Apr 18 17:02:28 EDT 2017

Thanks for sending this, Abram. I've long wondered if Limestone was ever used on heavy main lines; a 1929 Maintenance Cyclopedia stated in the ballast section that the best ballasts have (among other things) low cementing tendencies. Limestones don't really fit that description. 

This is probably an "availability trumps perfection" situation. 

Matt Goodman
Columbus, Ohio

Sent from my mobile

On Apr 17, 2017, at 8:49 AM, NW Mailing List <nw-mailing-list at> wrote:


One thing that always amazed me when hi-railing MW people and bosses who had spent time in the MW Department, was their ability to determine at first glance which quarry had provided ballast, based solely on the color of the stone.  I never developed that knack...

Another consideration for you:  Over the years, most railroads have switched from limestone ballast to "Trap Rock" ballast.  Trap Rock is a variety of granite.  As it was explained to me by those who knew (or should have known,)  limestone ballast degrades after about 20 years, due to acidic conditions and pounding of the roadbed, whereas Trap Rock does not.  I am guessing that this transition began in the 1980s;  Stanley Crane insisted on Trap Rock.

My knowledge of MW things is next-to-nothing, so take the above FWIW, cum grano salis.

-- abram burnett

                  Sent to You from my Telegraph Key
Successor to the MAGNETIC TELEGRAPH LINE of 1844

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