Cooling the water discharge on steamers

[Guest]

The actual boiler water is not what is in question here. It is the cooling water that is used to condense the steam back to water so that it may be reused in the boiler. Steamers have a condenser (heat exchanger) that has lake (or sea ) water pumped through it to take the remaining heat out of the water (after it has passed through the turbines). This water is pumped through the condenser and back into the lake. I sailed 20 years on my Engineers license and never heard about any regulations on our condenser overboard discharge. The fish sure liked it though!

[Dave F]

The January 1975 issue of Trains magazine has an article by Geroge W. Hilton entitled "Great Lakes Car Ferries: An Endangered Species." If you like Mr. Hilton's 1962 book "The Great Lakes Car Ferries" this article is a good update of their status in the mid-70's. Writing about the C&O fleet, he says their three steamers (Badger, Spartan, City of Midland 41) "raise the temperature of the water they use about 25 degrees between influx and efflux. Future Federal regulations will require this to be reduced to almost zero, and dealing with the problem would be virtually impossible." He goes on to say that the high cost of replacement diesel ships could not be justified given the unprofitability of the ferry service.
My question is, did these Federal regulations ever take effect, and if so, how do you lower the temperature of a ship's boiler water before discharging into the lake?
Thanks!