The following are the newest photos from the turntable project in Altoona, PA at the Railroaders Memorial Museum. Track work will commence in a few days once the wall is backfilled.

http://www.railroadcity.com/gallery/index.php?id=77

http://www.railroadcity.com/gallery/index.php?id=78

http://www.railroadcity.com/gallery/index.php?id=79

http://www.railroadcity.com/gallery/index.php?id=80

Thanks

Nice work. Please keep us posted. Also more technical information on the K4 restoration work would be great.

Can you tell us what the final concrete and steel tally came to?

Thanks, Chris Allan

Spectacular!!!!!! What weight rail did you guys go with?

The ring rail came with the table we purchased and it is 130PS. We were the beneficiary of a large donation of 130RE rail which will be used throughout the yard.

Thanks

We used 1008 cubic yards of concrete and I dont know exactly how much rebar was used but there were 4 tandem loads of steel delivered. Nearly 300 cubic yards of concrete was involved just in the 52 caissons that were poured before any concrete appeared above grade.

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What was required in the way of rebuild work? bearing, outer wheel bearing boxes, or structural?

The table itself was in very good shape when we obtained it. We needle-scaled the table and it is mostly in primer paint at the moment. The ends of the table where the trucks attach needed some minor structural work and that is in progess. The motors have been completely rebuilt for us by Electric Motor Supply here in Altoona. The trucks have been disassembled and we are in the process of working with ORX Corporation here to convert the friction bearings to roller bearings.

Thanks

Which is probably a mistake. Friction bearings will last several lifetimes in this slow speed service, are robust, and can take the pounding of engines moving on and off the table. The worst that can happen is the bearing fit will get a little sloppier, but who cares, the speed is slow. Roller bearings are much more easily damaged by sharp impacts. The one saving grace in this instance is this is a twin bridge table, so the end won't drop as much when an engine moves on as a single span table would.

Does anyone know of a successful conversion of trustable trucks to roller bearings?

The Conrail (Fromer Lehigh Valley) turntable at the Oak Island Diesel Terminal was converted about twelve years ago from friction to roller bearing. A typical AP style F (6-1/2" X 12") bearing was used in the conversion. We have had no trouble with the conversion. IIRC similar conversions were performed at Enola, Conway, and Altoona. UKM of Kulpsville, PA did the machine work on the OI table.

EBL

Mr. Levin,

Just to complete the information, would you happen to know if the turntables you list as converted to roller bearing are all twin span bridges? Since the ends of these always bear on the trucks, there should be no drop as an engine moves on and off, whereas there is on a single span balanced turntable. I'd sure hate to see a group spend scarce funds on a conversion only to have it fail prematurely from dents hammered in the bearing races. Then again, if this has been successfully done on a balanced turntable, that would be reassuring.

Thanks,

I believe all the tables I mentioned are single span balanced design.

EBL

Regardless of whether or not a table is initially constructed in one or two pieces is fairly irrelevant. The critical difference in design is that of a table being of a tri-point or balance design. Most all large tables(and all tables above a certain length) are of the tri-point design, this means that the outer load bearing wheels at each end of the table are always in contact with the rail....even if the table is of a single span design. This means, that the wheels do not move vertically and thus there is virtually no shock on the bearing and what shock there is (because of designed internal clearance on fits) on each individual bearing is minimal at best (and less than hitting a frog or joint in normal service) as there will be 8 bearings taking up the load of only one axle of the piece of rolling stock at a time and after the intital loading of the first axle the ramaining will really only increase the load. And this one......is most certainly of the tri-point design.

One more question for Mr. Cessna, what is/was required for repair of the center bearing? The table I rebuilt in Savannah was in horrible shape, I sent the center bearing out to Mr. Lindsay and was blown away by what I got back.......seemed like a crime to put it back in the pit. Also, I am curious as to what type of device will be used to provide for variable speed.....did you actually end up with a good vintage controller?

The 85' 8" three-point suspension table I ran for 20 years in St. Albans was built in 1923 with roller bearings by the American Bridge Company. It is still working today. After I received a slight buzz off the 440-volt controller once, a cocky hotshot young electrician tore everything apart. While awaiting the new control box, we had to pull the table around with a bucket loader for 8 months. The new controller and shanty functioned well after finally being installed, but a lot of history was lost for lack of some insulation on a wire. The guy was later fired, but came back as a scab when the new company took over and is now the head honcho; no need to ask why I'm not there anymore. Even though Altoona's table is a new non-historic installation, I hope they'll install a proper streetcar-type controller and not one of space-age design. Has anyone ever tried to convert an old controller to low-voltage operation for more safety?

Our center bearing was in very good condition; I would have to guess that it was rebuilt not long before it was removed from service. We removed the top portion of it for an inspection and found both the brass and the steel top to have a mirror finish and no scratches in it.