Question about old Southern whistle post

[railroad65]

On eBay is listed a OLD SOUTHERN WHISTLE POST it has 2 long and 2 shorts for the signal. I have never seen this pattern before, where would it have been used and the reason for the differince.


http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=4124&item=6541218939&rd=1


Thanks,
Railroad65

[Anonymous]

Here's a site that might help answer your question. About two thirds down the page there is a section on whistle signals. http://www.cprr.org/Museum/FAQs2.html Basically, at one time, railroads used the long long short short signal, but changed it in the 20s or 30s, perhaps so that the last long whistle could be carried all the way through the crossing, instead of a short whistle possibly ending before actually getting to the crossing.