manson-navvy-working manson-navvy-idle

Working Steam Navvy

On a tourist visit to Alcatraz I came across this giant steam powered navvy floating crane helping out with the dockside construction. Being construction workers they were not exactly helpful about letting me get near the crane, and there was no way to talk to the crane driver to get more details...

It is quite awesome to watch this enourmous machine slew, derek and hoist in almost total silence. Usually all you can hear is the roar of the huge diesel driving the hydraulics which operate the crane, with this one you can hear the steam engine(s) working and the creak of the cable and jib as they take up load.

I think the unit is Derek #24 from Manson's fleet, and their page had this informaton:

200' x 84' x 13' 400 Ton Capacity Derrick #24 is Manson’s heavy lift derrick that can usually be found working in the Puget Sound. She has also worked in Canada, on the Oregon Coast and California. Because of the smaller barge size and the ability to remove the pontoons from the barge, the #24 can fit into smaller spaces than other cranes with her lift capacity. Derrick #24 has also been utilized for driving large piles up to 144" diameter.Visit Manson's.

I've had some feedback about this machine from John Lucas Location: Sacramento Email: prontopower @AT@ gmail com Blurb: The manson steam crane on your site is the Iner.... It is a1940's vintage American R-32 whirly on a 52' x 110' barge.. Capacity is about 50 tons @ 100 ft radius.. I rented the Iner once for a bridge project when all our derricks were busy...It has since been repowered to diesel electric... I had a very similar crane which was also steam powered which I repowered to diesel hydraulic.