Topic starter
12/07/2014 8:10 am
I was recently chatting with another river enthusiast, it's better to call a well respected artist "river enthusiast" than a river rat, discussing the AQ's bad habit of breaking shafts. My father once surmised the cause was that the engineers don't use the valve jacks while handling the boat and setting the engines to come ahead or back. Not using the valve jacks to release the pressure on the pistons and torqueing the shaft was as bad as keying the boat's pitmans while on center, not blowing down a high pressure boat's mud drum often or for a long enough period of time, or not carrying the boiler water high enough. All of these being a recipe for disaster to an old time steamboat engineer.
In the back of my mind I remembered what Alan L. Bates wrote in his magnum opus BELLE OF LOUISVILLE: Ohio River Steamboat published by Howell-North Books; Berkeley, California; 1965. So on page 92 he writes about:
Handling the engines is no mean trick. To shift the engines of the BELLE from a forward motion to backing involves several operations. First, the throttle must be nearly, but not completely closed. Next the admission valve levers (valve jacks) must be lifted so that the steam may pass through the engines to the feedwater heater. Can't afford to chill the heater or the boilers, you see. Then the reach rod must be lifted so the yoke engages the upper pin on the rocker arm shaft. After that the admission levers are lowered to the rocker arms and the throttle opened. It is opened quite wide to start the heavy wheel rolling and is throttled to the desired speed. After all this the engineer must move the telegraph handle to let the pilot know that he has understood.
This must be done each time the pilot calls for a change of direction...
I thought that I would bring this up as some food for thought, and see what others more knowledgeable might have to say. Dan, Mac, Steve, Kenny, Tom, Scotty, or Chris are you listening?
14/07/2014 5:01 pm
Something is decidedly wrong with the AQ steam engines. When I was on the boat last summer, it took them about a half hour to warm up and the engines had a very bad lope and in order to keep the wheel turning, they had to warm up at about 10 rpm. All the other boats I've seen warm up, the engines turned about 4 or 5 rpms.
A boat just doesn't break as many shafts as the AQ has.
I'm no steam engineer but if I were them I would get someone like Chief Kenny Howe to come on there and make a thorough inspection of the steam plant and the engine valve settings. Something is definitely wrong. The NATCHEZ has been running 35 years without a broken shaft and the BELLE has been running 50 years here in Louisville without a shaft problem.
I do believe the problem is in the engine valve settings and not the design of the shaft.
14/07/2014 9:31 pm
There may be several issues with the AQ design. First, I believe that in '95 it was actually the starboard crank that broke, not the shaft per se. If you observe the crank design, it is a very light duty, hollowed out assembly, not solid like the DQ's. Also the stroke seems very short (6'?) for a wheel of that diameter, which would add significant stress. I may be wrong on this but I was told once that the shaft itself is hollow. Add to that Jim's account of improper engine set up...stuff happens.
14/07/2014 11:47 pm
handling steam machinery
The question remains just where did the shaft break? and is this the same problem as previous or is the crank yet another problem?
Topic starter
15/07/2014 12:34 am
The last crack was right in the center of the shaft between the two inboard flanges. I do know that the first crack was in the shaft, and it was not in the Nordberg style cranks. Shortly after the first time the shaft cracked I was a passenger onboard, and I could see where the old shaft was cut off inboard of each the two cranks. I'm not sure where the other two breaks were.
15/07/2014 1:36 pm
I observed the AQ at lock 16 on her maiden UMR voyage. From where I stood, I could see that the starboard pitman was unattached, and the wheel had been tied off. It certainly appeared to me that the crank was broken, but maybe not.
16/07/2014 11:33 am
Aside from the possibility of rough/improper handling of the engines, I wonder who manufactures the AQ's shaft(?). Hopefully it's U.S. made, and not made in China from U.S. scrap steel shipped to China.. Does the manufacturer test for flaws in the finished shaft? I would think someone would "Zyglo" or "Magnaflux" the entire shaft to make sure there are no flaws before installing it. (same for the cranks as well). Just a thought..
26/07/2014 12:34 am
I've "chewed the fat" with other engineers over this broken shaft--can think of a number of scenarios that may cause such a problem, but I haven't gotten enough solid information to come to any conclusions. I've often wondered what sort of stresses are put on her shaft when shipping "on the fly." After operating the Belle's engines, it took some time to get used to making this "sudden" change in direction on the AQ. Her engines are also extremely "cold-natured". In other words, we had to be very conscious of how her cylinder drains were set when locking, landing, and departing. Even after several hours of continuous use, coming out of a lock without opening her drains enough could be catastrophic! The loudest water hammer I ever heard was from those engines--sure will make a believer out of ya! Anyway, there are many possibilities to imagine in causing her shaft to break. As the saying goes, I haven't heard "the rest of the story" yet.