Steam & Excursion > ORHC - turntable update

as we head toward the first runs of our Holiday Express 11/25 out of the Oregon Rail Heritage Center, here are a couple of today pictures of our turntable project....next up is the building of forms for the pivot "pour" that I believe is scheduled for early December.  

I would expect to see many pictures of our Holiday Express consist pulled by the Polson #2 on one end and the UP 96 on the other.   This coming 3-day weekend is our first of four weekend runs.   
'
Happy Thanksgiving to all !! Arlen

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Nice. Great progress. Please post photos of the "indent" in the pit wall for access to the turntable bridge motors/trucks. Thanks again.

The maintenance "access areas" will be at the level of the.7-ft. tall, re-bar posts
that are sticking-up, and surrounding the outer edge.

The lower ring that was just completed, will be where the pit-rail will be secured on to.
The pit-rail is right over the pilings driven at the circular edge of the pit, as it 
should be to adequately support any unbalanced weight on the turntable 'bridge'.

They have yet to place the 2 rows of forms that will make the pit's wall...

Its really starting to take shape.

​Wes.

HotWater Wrote:
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> Nice. Great progress. Please post photos of the "indent" in the pit wall
> for access to the turntable bridge motors/trucks. Thanks again.

Here it is and its physical size is a big improvement compared to the one at the Brooklyn Roundhouse.

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Is it just me but I don't see any evidence of a drain in that pit or will they install a drain later, hopefully before they install the concrete for the pit.

Love the progress photos, thanks for posting.

I presume there is more substantial support to the center pivot than just the four pilings visible, yes? 

Desmond Praetzel, "4451 Puff"

I have been wondering the same thing as Mr. 4451.  If a loco is supposed to be balanced on the turntable, wouldn't almost all the weight be taken by just those 4 center pilings?  I can see the ring rail pilings taking a load as the loco goes on and off the turntable, but they seem to be overkill especially compared to the 4 center pilings.  

Arlen, I don't recall reading what the final costs will be to complete the turntable.  Is that public info?
Just curious.  HappyTurkey Day to you, your family and the entire ORHC Family.

thanks Joe.....I don't think we know the final cost will be yet...A letter I received today dated 11/30 closed with a generic ask so maybe enough $ are in hand for the turntable project but I am also hearing rumblings about a short term loan.   Arlen

ONE piling, carrying an end-wise load is strong enough to support
a 400-ton, or greater load.

The steel pilings are driven to solid, un-yielding support;  the 4, together, cannot move,
bend, or get out of place.  You are not going to compress that steel by any measurable amount.
The individual steel pilings are relatively immense, compared to the vertical loads
that will be applied..

You are compressing tte steel beam against it's strongest dimension.
It will not, and cannot yield by any locomotive weight.  

As in most similar cases the center members are designed to support many times the
actual weight that could conceivably be applied.

It's Thanksgiving, I'm adding ORHC to my list of amazing things that I have experienced,
over the last 82-years.   I'm so glad to have had friends like Ross, Doyle, Bruce, Joe, Dale,
and hundreds of other supporters.  I feel that I am truly blessed, to have been able to live
such a rich life, and I've had the support of so many folks ---- it's truly unbelievable.

Thank you, all.
And, thanks to my Creator.

​W.

Kimball Wrote:
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> I have been wondering the same thing as Mr.
> 4451.  If a loco is supposed to be balanced on
> the turntable, wouldn't almost all the weight be
> taken by just those 4 center pilings?  I can see
> the ring rail pilings taking a load as the loco
> goes on and off the turntable, but they seem to be
> overkill especially compared to the 4 center
> pilings.  

The answer to your question is that the the turntable bridge is not perfectly rigid; it deflects under load.  If the bridge were supported entirely by the center bearing (perfectly balanced) and the perimeter rail wasn't there, the ends would sag below the level of the perimeter rail.  On the other hand, if the center bearing weren't there and the weight was supported entirely by the perimeter rail, the center of the turntable would sag below the level of the center bearing support. 

Having 3 supports is an example of what's called an indeterminate structure, where the support loads cannot be calculated from the applied loads and their locations alone.  Structural stiffness and deflection must also be accounted for.

Turntables prior to about 1900, where the bridge structures consisted of tall A-frames, were designed to be supported entirely by the center bearing.  The combination of a tall truss structure and relatively light locomotives made that practical.



Edited 1 time(s). Last edit at 11/24/22 14:42 by Elesco.

Wes, you may have some idea with all those friends how much you are appreciated for your knowledge and your significant contributions to the AFT and 4449 Family.

Weather,
Thank you for your kind comments.

I was just thinking about what a wonderful outcome the affairs with 4449 have been.

It originated with my thinking about our 1969 experience with NKP 759 and the 
Golden Spike Cenennial Limited, and the cross-country experience we had with
a coal burner.

The problem was a mis-match netween the super-powerful capacity of the 759 and
the trailing weight of only 14 passenger cars.   The grates, the proportions of the
drafting-jet & the smoke stack 'Venturi' were all designed for pulling 80 car freight 
trains at high track speeds.

With only 14 cars, the air through the grates was a breeze, instead of a tornado...
The result was that the ash and fky ash built-up on the grates ---- whereas, with a 
heavy freight, the velocity of the wind through the grates swept all that light ash 
right up the stack, and the rocking oh the finger grates sifted the heavier stuff into 
the ash pan...

So, when we were considering the up-coming AFT,  I was mentally committed to 
using an oil burner for the vast stretches of America and the wide-open Plains.

I had known about the Daylights only peripherally, being an East-Coast kid.
But, as I explored the possibilities, I found my appreciation for the excellent 
design skills of LIMA Loco, and the esoteric lines of the Daylight locos.. 

So, as the calendar ticked off the days, I entered a period of 'mental burn-out' 
about the AFT, the political nastiness at the time, and lack of direction with AFT.
i was grouchy, short-tempered and deeply cynical... not a good combination 
for the responsibilities of heading-up the Loco-Team.  
So, I left, got married to a wonderful womsn, went railroading, full-time.  

About 4 or 5 months later, I was asked to explain my earlier preference for the
engine at Portland,   I attended a staff meeting in Washington, DC, , and explained 
my thoughts...... I declined a job offer, but recommended Doyle as the best candidate
for getting 4449 operational, if it was operable.   

Doyie, luckily accepted the task, when AFT contacted him.....
Before deciding, Doyle called me on the land-line ( back in those days)
to ascertain that my separation from AFT was irrevocable, and that 
I would not return at some future date ...

I assured Doyle that my mind was made-up, and that he need not worry about
that kind of eventuality.  My separation was permanent, but my commitment to
support the project was deep, and my commitment to my friends on the loco
setvice team was also deeply embedded.  I was totally supportive of getting
the 4449 operational..... if it was possible.

I told Doyle, " You'll have only one chance to change your life, forever, 
                       Don't pass-up this opportunity.  Joe ( boilermaker) will be with
                        you every step of the way!   ...'

Now, here we are at the doorstep of almost the 50-year mark, following 
Doyle's agreement to lead the Team and the effort to return the 4449 to
operation...

Things could have turned out a lot differently if any  simple event or occurrence had gone
differently.  It's inconceivable that every single decision point, all lead to where we stand today..
And a huge part of that success is the 'can-do' attitude and the support of the City of Portland,
and the capabilities of the Portland citizens to accomplish the early goals..

There are a LOT of other possible oil-burner locos that could have been considered...
But, no others had the backing of the folks in Portland..

That's the story of why I give thanks this time of year, every year,  for ALL that has been accomplished...
​In Portland and with the 4449.... because Doyle said: YES !!
 
Wes Camp

( Oh yes, Ruth and I are happily married, semi-retired, and are approaching 
   a 50th Anniversary....together.  I'm blessed in SO MANY ways, with so many friends,
    like Doyle, Ross and a thousand others...and a HOT 4449! to boot!, complete with
    turntable !!)



Edited 1 time(s). Last edit at 11/25/22 05:16 by wcamp1472.

Elesco Wrote:
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>
> Turntables prior to about 1900, where the bridge
> structures consisted of tall A-frames, were
> designed to be supported entirely by the center
> bearing.  The combination of a tall truss
> structure and relatively light locomotives made
> that practical.

Correcting my earlier paragraph, center bearing “balanced” turntables on the SP were built in the early 20th century and used in some locations until the end of steam.  They were built primarily before 1920, while later turntables, particularly the longer ones, were of the continuous type with 3-point support.

Photos posted below:

1.  This is an example of a center-balanced turntable, the 100-footer at SP’s Mission Bay Roundhouse in San Francisco.  Note the complicated through-truss structure, needed to limit stresses and deflections resulting from the long overhang from the center support to the ends of the bridge.  Similar tables were used at Bayshore and San Luis Obispo.

2.  The future ORHC turntable as installed at the Brooklyn roundhouse.  It was manufactured by American Bridge Company in 1924 and installed in 1925.  It is also 100 feet long, but has much lower section because it is of the continuous type.

I don’t know of specific examples, but some center-balanced turntables were constructed with all of their structure below the track.  They had the disadvantage of requiring a much deeper pit.

 

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Wes, thank you VERY much for your great posting......included with this posting is one of my favorite photos.    the milepost is now a part of our AFT exhibit at the Oregon Rail Heritage Center, Portland.  my thanks to Todd S for saving the milepost.   (sorry for how my photo posted, and this was with a camera.) Arlen

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What does the number represent?

Wes Camp

I do believe that the number represents the total number of miles traveled by the American Freedom Train during 1975 and 1976.

I am also curious about what type of material or fill or concrete will be placed in the turntable pit area. Remember the ground where the turntable is being installed is "fill" into a previous slough/wetland area of the Willamette River, mainly sawdust and other debris. Note that Portland gets about 36 inches+ of rain a year. Maybe leave the entire area very porous to let water pass thru? Or does it need to be sealed from any water penetration to get below grade? with an appropriate drain?

TTStetz3 Wrote:
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> I am also curious about what type of material or
> fill or concrete will be placed in the turntable
> pit area. Remember the ground where the turntable
> is being installed is "fill" into a previous
> slough/wetland area of the Willamette River,
> mainly sawdust and other debris. Note that
> Portland gets about 36 inches+ of rain a year.
> Maybe leave the entire area very porous to let
> water pass thru? Or does it need to be sealed from
> any water penetration to get below grade? with an
> appropriate drain?

I was wondering about the same questions.  I'm not a civil engineer and I don't live in Oregon, but I checked with Google and found a document entitled, City of Portland --Stormwater Management Manual.  A quick Google search leads you to the downloadable pdf.  It provides a lot of guidance regarding design and legal requirements.

As my own uneducated guess, I don't think it would be feasible or desirable to put 36 inches of rainwater per year falling on the pit into the soil directly underneath.  At least in major rain events, there must be runoff provision, which my guess would be a connection to an existing storm drain, probably under the adjacent street.  Hopefully that would be low enough to drain the pit.  That connection should not put a new burden on the existing city drain system, as before the pit, I believe the area was paved.  Rain on the pavement would have run off into the street, and then at some point into the storm drain (and on to the river).  So a drain from the pit would be a re-route, not a new load.

Perhaps a porous bottom of the pit would be a desirable adjunct for handling frequent light rain events.  That would be a question for the city as to where they want the water to go, perhaps integrated with their plan for stormwater management in the upcoming large housing development between ORHS and the river.