NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: OT: Interesting video
From: Lu Abel
Date: 2013 Dec 16, 15:53 -0800
From: Lu Abel
Date: 2013 Dec 16, 15:53 -0800
The San Francisco Liberty Ship is the SS Jeremiah O'Brien, docked
near Fisherman's Wharf and part of the National Maritime Museum in
SF.
In 1994 the O'Brien steamed under her own power to Normandy to mark the 50th anniversary of her participation in the invasion.
She still makes regular trips in SF Bay under her own steam -- but has to be escorted by two tugboats since Liberty ships had but a single engine and an engine failure on the O'Brien could turn her into a uncontrolled ship aimed at a populated waterfront. I also understand that she has a very large turning radius and needs help from the tugs to do a U-turn despite SF Bay being five miles wide.
Long and interesting article on Liberty ships in Wikipedia: http://en.wikipedia.org/wiki/Liberty_ship
including why they were called "Liberty" ships and how individual ships were named.
The article also discusses the ships' proclivity to hull fractures, with at least three splitting in half and sinking (arguably not bad, since over 2700 were built). It turns out that this occurred mostly during winter passages from the US to Britain. The steel in the hulls actually turned from ductile (which would give a little under stress) to brittle (which would snap under stress) at temperatures in the low 30s (Fahrenheit, or a few degrees above 0 C).
It's not clear from the Wikipedia article how the ships were compartmented.
In 1994 the O'Brien steamed under her own power to Normandy to mark the 50th anniversary of her participation in the invasion.
She still makes regular trips in SF Bay under her own steam -- but has to be escorted by two tugboats since Liberty ships had but a single engine and an engine failure on the O'Brien could turn her into a uncontrolled ship aimed at a populated waterfront. I also understand that she has a very large turning radius and needs help from the tugs to do a U-turn despite SF Bay being five miles wide.
Long and interesting article on Liberty ships in Wikipedia: http://en.wikipedia.org/wiki/Liberty_ship
including why they were called "Liberty" ships and how individual ships were named.
The article also discusses the ships' proclivity to hull fractures, with at least three splitting in half and sinking (arguably not bad, since over 2700 were built). It turns out that this occurred mostly during winter passages from the US to Britain. The steel in the hulls actually turned from ductile (which would give a little under stress) to brittle (which would snap under stress) at temperatures in the low 30s (Fahrenheit, or a few degrees above 0 C).
It's not clear from the Wikipedia article how the ships were compartmented.
On 12/16/2013 2:19 PM, Jackson McDonald
wrote:
