is there anybody who has access to/or knows of pictures, drawings, modells etc. from the California Cut Off System plus Spider for valve gears. We found this drawing in a book and are interested to know more about this design, it's history and vessels which was powered by it. The Delta queen has a Californis Cut Off System but without a Spider...
All comments are welcome!
2013-06-25.201401.jpg (33.91 KiB) Viewed 14774 times
Rainer,
The following site file 10I has the valve linkage animation for the Wertern Rivers California style variable cut-off:http://www.jf2.com/bcwrr/Dockstader-Valve-Gear.html
I've also found a couple photos of museum models that are to small to derive any detail.
As time permits I do volunteer work on the Sternwheel tug Portland that handled ships in Portland Oregon until 1972. She has two 24" dia. cylinders with about a 10ft. stroke and piston valves on the variable cut-off. This is completely differant from what is common on the "Western Rivers". On the lower Columbia we live where "Out West" is east!
This is a picture of the cut off spider on the snag boat Preston that is now on dry display in Anacortes, WA.[img]http://i1275.photobucket.com/albums/y45 ... 8e.jpg[img].
I photoshopped in some annotation.
From what I have learned is that this system was originally a West Coast invention( thus California Cut Off) that was successfully addapted for the lever arm engines of the Mississippi River system.
You will that the pictured system is operating piston style cut offs, but this system can be used to slide and space the wedges used on the lever arm engines.
This is my first try to post a phote so we'll see if the picsuls will make it?
]Hello Rainer, I have just been handed your request for CCvalve gear info by a pal who has a fullsize steam boat (nearing completion) I am in the process of making a model of the Delta Queen engines (see pics) Like you I am keen to sort just how the valve gear works if my first display model will work I then intend to make a half size model as this will result in a hull (for model ) of approx 60" . Basically the poppet valves are lifted at the correct time by the valve bars (through the middle of engine) These are under the control of the excentric on the stearnwheel main shaft , each inlet valve has a sloping wedge fitted on the valve bar just bearing on the lifter for the poppet valve (advancing or retarding) the cutoff point . this is controled manualy and also by the rod from the cross head ,(Don't ask )have yet to work it out myself, AM using data from Ageless Engines (not sure it is all corect ) there is a video on U tube Buy a gent( Delta P Mech ) showing a model sternwheeler engine under test , Its a very difficult system to describe hence I am doing the model. If my first attempt at a display one works (at this scale would result in hull length of 12ft)
to Big for practical purposes , Then the half size model will be attempted as per Delta P Mech
Trust this may be of some help , come back if I can assist further C/P
Just a footnote for those who may not be aware, the sisterships, Delta Queen and Delta King, were originally built for and operated for the scheduled passenger run between San Francisco and Sacramento, California, on SF Bay and the Sacramento River. The "delta" in their names referred to the California, rather than the Mississipi River delta. The Delta Queen was taken through the Panama Canal to the Mississippi River after WWII and began tourist tour operations there at that time, earning her fame. The Delta King, now nicely restored, is berthed in Sacramento, CA, as a floating tourist hotel. Her steam plant was removed long ago.
