several turntables have been installed over the past 20-30 years. I've heard some problems which came up and maybe could have been avoided with better engineering. Can people share the problem areas to be avoided? Also, does anyone have a set of engineering drawings which could be used as an example for specific engineering drawings for a specific turntable?

Many thanks.

Wood or steel? Deep pit or shallow? Length? Wanting to reproduce a particular style/era?

For the smaller power I prefer, I'm a big fan of the SP gallows turntable which Nevada State Railroad Museum has reproduced. No concrete pit to fall into, minimal mechanical requirements since it is not powered by machine.

I believe there were 4 sets of castings poured from the patterns for the NSRM Carson City turntable... (the patterns still exist) one for Carson City, one for Orange Empire, one for Folsom CA and the 4th so far unused. Additionally there is an original SP turntable of the same design in Laws at their railroad museum.

This turntable design came in several "flavors"... built by the Carter Brothers and Southern Pacific among others, originally it was without ring rail... The Carson example has a ring rail.

By the way, under FRA rules, turntables are bridges (span being half the length) and will trigger the need for a FRA bridge management program, even if the railroad is otherwise Un-regulated... We include the Carson turntable in the Boulder City bridge plan under Nevada State Railroad Museums.

I understand that the Colorado Railroad Museum has a bridge management plan, solely for their turntable.

Randy

A little large, but you can read it....

That's nearly identical to the drawings in this thread:

viewtopic.php?f=1&t=39624

Coincidentally, this week the WW&F (2ft gauge Wicasset, Waterville and Farmington Ry in Maine) is pouring the base of their new turntable in Sheepscot (the whole thread is 14 pages long but I linked to to photos from yesterday):

http://forum.wwfry.org/index.php?topic= ... 3#msg28473

I understand that the plans are based on reverse engineering from turntables that existed in both Wicasset and Albion on the original railroad, the bridges of which were produced by the Portland Co., which also built several of their steam locomotives and freight cars. As they always do, they have gone to great pains to ensure historical accuracy.

To add to the WW&F Turntable being installed in Alna, ME:

It's construction was funded, in part, by the Amherst Railway Society's Founder's Award - and we thank them for their generous donation.

The Portland Company designed the table, and we used the original drawings for our design, etc. We only made a few adjustments. The original WW&F had nearly identical turntables of this design in Wiscasset and Albion Maine. The replica is essentially the same.

It will feature a 48-foot wooden queens post turntable bridge. To our knowledge, there are no surviving examples of this design.

From my contacts with many folks who obtained and fewer who installed these the biggest problems have been caused by trying to cut corners, using cheap alternatives to solid engineering. Every installation is site specific and generalizations are not very useful. Having a reputable engineering firm evaluate the proposed site, check the water table, do test borings and soil evaluation is critical. Every place is not suitable to every design of turntable, which is why different designs exist. In one case a table was installed by a contractor who insisted his cheaper methods were just fine and I doubt any engineers were involved. After it was in place the owners found the center bearing supports shifted a bit every time it was used, which as a result was rare. Fortunately it wasn't expected to be used constantly, and was only used on special events. Eventually the outfit moved which eliminated this problem. Beware of bargains that sound too good to be true.

Amen to that.

Once the WW&F did the engineering designs for our turntable pit and pedestal, we realized we would need $35,000 worth of concrete work for the footings, rim, etc. (We had budgeted a LOT less.)

So, in our case, we did the rebar and form work ourselves, saving considerable expense (but adding to the time required to complete the project.) We're still hoping to have the table assembled for the National Narrow Gauge Convention in September, but it's going to be tight.

Randy,
There were four sets of castings poured after the Carson City turntable was constructed. Orange Empire and Folsom were used to construct turntables. IIRC, the other two sets went to an organization in the Placerville or El Dorado County area, California, that was proposing to build a three-foot(?) gauge line. This may have involved the former Diamond & Caldor Shay #4.

The Laws turntable is similar to the standard SP design; I've been told that the castings for the pivot, etc. are different and may be reused from an older turntable on the old C&C.

Orange Empire added a concrete foundation under the traditional wood cribbing for the center pivot.

As someone who worked with an Armstrong turntable in standard gauge, I would suggest a motorized turntable for an organization comprised largely of volunteers. Armstrongs work well, but a bit of skill is required to properly spot the equipment over the balance point. The narrow gauge folks have the advantage in that their equipment is generally lighter and more forgiving. Campo has many items over 100 tons. This gets a bit trying to turn by hand. Have you considered a used table? There seems to be quite a few spread out in the dingweeds. Or perhaps you have one, and are looking at the installation?

Yes, we own a 70' turntable off the AT&SF from Fresno, I believe. It's an electrical one. The footings for the center plate and the side plates are of interest.

Do I recall some problems with the installation of the turntable in Sacramento or elsewhere? What lessons were learned?

Thanks.