The 600-footers were a class of lake freighters all built to the design of the ''J. Pierpont Morgan''. The ''J. Pierpont Morgan'' was launched in April, 1906, and was, at the time, the longest vessel on the Great Lakes. Her sister ships were not all identical. Minor modifications were made. Mark L. Thompson, author of '' Queen of the Lakes'', wrote that between 56 and 76 vessels were built to this design. The 600-footers could use harbours that larger seawaymax vessels can't use. Until 1961 no vessel longer than 600 feet was able to access

Cleveland Cleveland ( ), officially the City of Cleveland, is a city in the U.S. state of Ohio and the county seat of Cuyahoga County. Located in the northeastern part of the state, it is situated along the southern shore of Lake Erie, across the U.S. ...

's harbour. The vessels' draught was . Their beam was . They were powered by triple expansion steam engines, providing , and could carry 11,000 tons of cargo. They cost $440,000 to construct, in 1906 dollars.

References

{{Reflist, refs= {{cite web , url = https://www.flickr.com/photos/upnorthmemories/40738597004 , title = RPPC SHIP FREIGHTER SS DG KERR built 1916 , publisher = Flickr , quote = RPPC SHIP FREIGHTER SS DG KERR built 1916 600 footer SS DG KERR and Pittsburgh Steamship Company SS WILLIAM A. McGONAGLE launched Real Photo Antique Photo Postcard Photographer UNK3 {{cite book , url = https://books.google.com/books?id=KRLZDXIEWCsC&pg=PA48&dq=%22Peter+A.B.+Widener%22+freighter#q=%22Peter%20A.B.%20Widener%22%20freighter , title = Steamboats & Sailors of the Great Lakes , author = Mark L. Thompson , publisher =

Wayne State University Press Wayne State University Press (or WSU Press) is a university press that is part of Wayne State University. It publishes under its own name and also the imprints Painted Turtle and Great Lakes Books Series. History The Press has strong subjec ...

, year = 1991 , isbn = 9780814323595 , page = 48 {{cite book , url = https://books.google.com/books?id=cp0-AQAAIAAJ&pg=RA3-PA49&lpg=RA3-PA49&dq=600-footers#q=600-footers , title = The Log, Volume 48 , author = American Society of Marine Engineers , publisher = Miller Freeman Publications , year = 1953 , page = 49 , quote = Until the 1920s this class of vessel was considered just about the ultimate in size. {{cite book , url = https://books.google.com/books?id=irtD2o_uQ88C , title = Queen of the Lakes , publisher =

, author = Mark L. Thompson , year = 1994 , isbn = 9780814343371 + Merchant ships of the United States Steamships of the United States