Steam & Excursion > Portable Turntable?

I know this sounds far fetched but would it be feasible to built a portable turntable as part of a flatbed pulled by a semi or hauled in by rail that would pivot on an axis?  I suppose this could be used as a semi-permanent set-up with a track connection on a ramp or fill.

Perhaps one would say the cost and trouble might justify just building a turntable, but what if it wasn't meant be permanent and it had to be moved to another location for reuse?

Maybe something similar in some form has already been built, particularly in the early days of railroading when inventions were devised to solve every problem or something was required in a remote location?

Victor B.

 



Edited 1 time(s). Last edit at 05/05/22 21:32 by wabash2800.

What's not seen that's under all conventional RR-turntables is the 
amount and extent ( depth) of driven pilings that support the turntable bridge,
as well as supporting the million pounds of locomotive.

Typically, you'll find a tight, square array of 16 central pilings, under the
center bearing, angled slightly apart at the piling's bases.

Watch the upcoming pile-driving process at ORHC, Portland, Ore.  
They've received the delivery, by rail, of the steel pilings to be driven
( pounded home!) over the coming weeks.

They're seeking to reach, way-down, firm ground to support the future weights.
Their contractor has conducted many soil studies in order to know how many
pilings to order.  The planning & Engineering at this level is deep and thorough, 

Its not just dragging around a 100-foot, steel bridge, in order to handle the massive-weight,
of mainline locomotives.

Also, it would help the ORHC, if readers would join me, & contribute to the funding needed 
to complete this massive undertaking.
Thanking you in advance.

​W.

How true W what you say is few understand the hidden structure needed to make one work. Its much like airport runways know of one that was rebuilt at an airbase for B52s. The concrete was 13ft deep. The bearings for the one they are getting ready to install at the museium were quite telling.

Just the turntable alone would be a massive load, even a small one. Let alone the infrastructure to support it and the weight of an in service locomotive. No, probably not realistic.

But what if it was centered and pivoted on the flatbed, like the ones that carry very heavy loads but from a connecting track in the rear? I mean, lowboy trucks and special duty flats can carry a lot of weight can't they? And perhaps outriggers could be added to stabilize the load? Yes, the flatbed would have to hold the weight of the turntable and a locomotive.

Victor



Edited 2 time(s). Last edit at 05/06/22 11:30 by wabash2800.

wabash2800 Wrote:
-------------------------------------------------------
> But what if it was centered and pivoted on the
> flatbed, like the ones that carry very heavy loads
> but from a connecting track in the rear? I mean,
> lowboy trucks and special duty flats can carry a
> lot of weight can't they? And perhaps outriggers
> could be added to stabilize the load? Yes, the
> flatbed would have to hold the weight of the
> turntable and a locomotive.
>
> Victor
Fine, do the research and the math. You asked those that know and we answered. But you keep asking, "But what if?". It doesn't change the physics. But hey, anything can be done with enough money and engineering, even if not practical.

Are you saying that the TT trailer would be 100 feet long,
carry a million pounds, and drive through cities and towns?

What kind of ramp tracks are you going to use to get up to the TT's rails?
You're NOT having a pit, right?
What propulsion scheme is gonna spin that TT?

How much would you charge the users to provide that 'turning service'?
Are you using ONE highway tractor to tow this thing, or two?
Who's paying for construction of this 200ft-long, complete rig?
How will you recover the costs to buildi it, how about the costs of the highway-use
permits, the police escorts that will be assigned, etc. etc?

What happens when you get this thing stuck, 'high-centered' on an active 
railroad main line?  
How you gonna get that thing un-stuck and off those tracks, and out of the way?
What highway bridges will take your weighty rig?
Which critical bridge crossings will you NOT be able to use?

​W.



Edited 2 time(s). Last edit at 05/06/22 13:48 by wcamp1472.

Thanks for all your input folks. It is just a hypothetical, that's why I'm asking.

Victor B.

Maybe a very small one for amusement park size engines could work, but why would they want or need it? They probably either have a way of turning or just don't really need it. For the price of hauling that in, setting it it up, using it temporarily, and taking it back down, I image a crane could do the work with less fuss.

Posted from Android

In 2017 we moved just a 100 foot turntable to our museum site. No ring rails, no center pivot, no outriggers or any other extraneous items, just the bridge, and just across town. It was expensive, took several days and lots of permits, roads and bridges we had to avoid and with a special steerable trailer and escorts. You would need a much larger and more expensive rig to do what you are talking about plus several support rigs with the equipment to set it up and cranes to move it all into position. And if you provide the approach track it must be level with the bridge for at least the length of the bridge, you can not go uphill onto it. Then the whole thing must be balanced on the center support, not the ring rails, to be able to turn it. The center support carries the entire weight of the bridge and the locomotive and needs to support about 400 tons perfectly centered. I have never heard of a portable turntable now or in the past because it is impractical. You build one where you need one at great expense with proper engineering.

---

wabash2800 Wrote:
-------------------------------------------------------
> I know this sounds far fetched but would it be
> feasible to built a portable turntable as part of
> a flatbed pulled by a semi or hauled in by rail
> that would pivot on an axis?  I suppose this
> could be used as a semi-permanent set-up with a
> track connection on a ramp or fill.
>
> Perhaps one would say the cost and trouble might
> justify just building a turntable, but what if it
> wasn't meant be permanent and it had to be moved
> to another location for reuse?
>
> Maybe something similar in some form has already
> been built, particularly in the early days of
> railroading when inventions were devised to solve
> every problem or something was required in a
> remote location?
>
> Victor B.
>
>  

No.

Posted from iPhone

It would be more feasible to build a snap track wye with jump frogs and panels.

Just build a ramp up onto a track set on a platform made of those remote controlled movers with a bunch of wheels. Make about a 50 point turn to get the locomotive spun 180 degrees and back down the ramp.
Fast? Nope
Cheap? Nope
Portable? Yes

I have seen photos of the German WWII K5 railway guns, nicknamed Anzio Annie, on turntables

These were "portable" but two guns required a support train of 24 cars to support them, besides the 22 cars for a two gun train

Tom Daspit
Morgan Hill, CA
Tom's Trains

Victor, In the Feather River region there was a power company railroad in the Caribu area. They had a shay that when it got to the power plant there was no room to turn the loco, so it went into a door in the power planet and was lifted with a crane, turned and placed back on the rails.

wabash2800 Wrote:
-------------------------------------------------------
> Maybe something similar in some form has already been built, particularly in the early days of railroading
> when inventions were devised to solve every problem or something was required in a remote location?

It would be easier to build an engine that pivots on a center point. Center cab and double cab engines remove most of the need for a wye or turntable. Your initial post did not specify that the turntable was for engines, but most other cars don't need to be turned (cars in unit coal trains that use a rotary dump would need to have the rotary ends aligned correctly).

I have seen a portable turnout in use (laid over an active main line to allow train cars to enter a siding from the wrong end. I thought that was innovative. Portable turntable? Not so feasible. But thanks for dreaming.