--- On Wed, 6/9/10, pullmanboss <tcmadden@q.com> wrote:


I learned that lesson

in my narrow gauge days, when I realized that very fine
chain could be represented by twisting two lengths of
extremely fine wire together. Very useful for those smaller
models, especially for chain wrapped around an operating
rod.

Tom brings up a subject that I feel needs to be promoted.

Commercially available chain seems to limited to 40 links/inch as the finest size available. Many chains we desire, need to be smaller.

A friend demonstrated to me how to make the illusion of finer chain by Tom's suggested method. He went a bit further.

Take a strand of dead soft copper wire (Armature wire seems to work well, and is quite fine)and double it. The looped end goes on a hook mounted to a secure base. The two free ends are fastened into a pin vise. With a steady slight pulling effort, twist the pin vise, creating tighter and tighter "Knots" as you twist. This is very much like the knots created by winding a rubber band in our balsa wood airplanes of our youth.

When the desired amount of "knots" is achieved (You will figure this out with practice) take this twisted wire and place the desired amount of "swag" you wish to your chain to have (similar to a parrabolla). Now place the wire into a smooth jawed vise, and clamp down HARD! This you will also learn with practice.

You will find that you have the perfect rendition of the 0-0-0-0 effect of chains. This illusion works only in one plane, but on my brake tie-down chain on my ALCO truck mounted brake cylinder the effect is wonderful. Everyone who sees this is impressed with the visual illusion of scale sized chain.
-Andy Carlson
Ojai CA

There is 52 links per inch chain available along with photo-etched 72 lpi
chain although it is two-dimensional:

http://www.traincat2.com/


Jack Burgess
www.yosemitevalleyrr.com

The bridges are beautiful. I need a single track pin connected Pratt Truss for my Alma branch layout. The one at the Traincat website is beautiful, albeit too heavy for my line.
Jared Harper
Athens, GA

Jared,

Have you examined the Central Valley bridge kit for a 150 foot Pratt Truss pin-connected single track bridge? Central Valley makes both an HO and N scale kit for this bridge. Here is a link to its website: http://www.cvmw.com/

The HO kit has been around for a while. The N scale kit is new.

Ken Montero

Steam era freight car discussion group. The time period covered will be from 1900-1960.On Fri, Jun 11 2010 at 4.52 am, Ken Montero wrote:

"Jared,

Have you examined the Central Valley bridge kit for a 150 foot Pratt Truss pin-connected single track bridge? Central Valley makes both an HO and N scale kit for this bridge. Here is a link to its website: http://www.cvmw.com/

The HO kit has been around for a while. The N scale kit is new."

I built the Central Valley 150 foot Pratt Truss bridge a few years ago. It makes up into a very nice model and isn't difficult although you do need to do a bit more than shake the box. I recommend it.

It looks great with a ten-wheeler and a brace of cars on it.

Richard White

The prototype for the CV bridge was on a branchline hense for lighter loads. In fact, to use it for mainline or heavier duty, you need to "beef" it up some.

Jerry Glow

I don't believe the Central Valley truss bridge is a pin-connected truss bridge. A model image is on their mainpage:
http://www.cvmw.com/

I'm more familiar with a pin-connected truss looking more like this one. Note the steel members along the bottom outide of hte truss.
http://www.texnrails.com/catalog/details.asp?sid=JF25697055421821&mfg=TMS&item=2200301&cat=&series=

Of course, material for either type of bridge most likely was transported in steam era freight cars to the building location.

Eric


Eric Hansmann
Chagrin Falls, Ohio
Modeling the railroads of Newburgh, Ohio, circa 1926.
http://designbuildop.hansmanns.org/

--- On Fri, 6/11/10, Eric <eric@...> wrote:







 









<I don't believe the Central Valley truss bridge is a pin-connected truss bridge. >








You are right, Eric. Although a pin connected truss may have some solidly riveted joints on the bottom member, sort of a combination of your two examples. I have kit bashed a CV kit to a pin connected deck truss.

CJ Riley

Eric Hansmann wrote:

I don't believe the Central Valley truss bridge is a pin-connected truss bridge.

You're certainly right, Eric, that the CV bridge shown is not a classic pin-connected bridge, with BOTH diagonal and bottom members being pin-connected. But it DOES have the diagonals presented as pin- connected. Mechanically, the CV bridge would be an odd adaptation. The whole point of pin-connected bridges is that with the joints among the bridge members able to rotate (slightly) under load, the truss was a determinant structure with the mathematical methods of the early 20th century. When those joints are rigid, there was not then a closed-form equation for stresses in all the members. So the CV bridge, with the pin-connected diagonals meeting rigidly connected top and bottom chords, doesn't serve the original purpose of pin connections. But it may make a bridge with slightly lighter members and thus slightly cheaper.

Tony Thompson Editor, Signature Press, Berkeley, CA
2906 Forest Ave., Berkeley, CA 94705 www.signaturepress.com
(510) 540-6538; fax, (510) 540-1937; e-mail, thompson@...
Publishers of books on railroad history

Eric is correct -- this is the Central Valley prototype in Piru, CA
http://www.bing.com/maps/?v=2&cp=pr2gdb530vcq&scene=11424394&lvl=2&sty=o

The CV web site says the bridge was built by the New York Bridge Co. It
was no doubt shipped in pieces some distance by rail, but might have gone
by ship to either New Orleans or even around the Horn before being loaded
onto freight cars.

Tim O'Connor

Hi Tim & Group,

I think that the bridge dates from the early 20th Century... something like 1902, I think. In this case you have the correct idea. But I would guess that it is more likely that it was shipped by rail instead of going around the tip of South America.

But there is a third route... by ship to Colon, Panama, Colombia (remember that Panama was a state of Colombia at the time), then transshipped over the Panama Rail Road (PRR... just love those initials), and then transshipped again up the west coast with the final delivery being by rail. Most likely still faster than going the extra miles around South America.

Cheers,
Bill Keene
Irvine, CA


On Jun 11, 2010, at 2:16 PM, Tim O'Connor wrote:

Eric is correct -- this is the Central Valley prototype in Piru, CA
http://www.bing.com/maps/?v=2&cp=pr2gdb530vcq&scene=11424394&lvl=2&sty=o

The CV web site says the bridge was built by the New York Bridge Co. It
was no doubt shipped in pieces some distance by rail, but might have gone
by ship to either New Orleans or even around the Horn before being loaded
onto freight cars.

Tim O'Connor

I don't believe the Central Valley truss bridge is a pin-connected truss bridge. A model image is on their mainpage: http://www.cvmw.com/
I'm more familiar with a pin-connected truss looking more like this one. Note the steel members along the bottom outide of hte truss.
http://www.texnrails.com/catalog/details.asp?sid=JF25697055421821&mfg=TMS&item=2200301&cat=&series=
Of course, material for either type of bridge most likely was transported in steam era freight cars to the building location.
Eric

[Non-text portions of this message have been removed]

Hi Bill,

            The Panama RR, was it standard, or narrow ga. ?
If narrow, you know there will be a car so lettered on a
PRR flat headed to a shipping point.

Fred Freitas
admitted SPF




________________________________
From: William Keene <wakeene@...>
To: STMFC@...
Sent: Fri, June 11, 2010 5:40:46 PM
Subject: Re: [STMFC] Re: PATCHING, and fine scale chain

Hi Tim & Group,

I think that the bridge dates from the early 20th Century... something like 1902, I think. In this case you have the correct idea. But I would guess that it is more likely that it was shipped by rail instead of going around the tip of South America.

But there is a third route... by ship to Colon, Panama, Colombia (remember that Panama was a state of Colombia at the time), then transshipped over the Panama Rail Road (PRR... just love those initials), and then transshipped again up the west coast with the final delivery being by rail. Most likely still faster than going the extra miles around South America.

Cheers,
Bill Keene
Irvine, CA


On Jun 11, 2010, at 2:16 PM, Tim O'Connor wrote:

Eric is correct -- this is the Central Valley prototype in Piru, CA
http://www.bing.com/maps/?v=2&cp=pr2gdb530vcq&scene=11424394&lvl=2&sty=o

The CV web site says the bridge was built by the New York Bridge Co. It
was no doubt shipped in pieces some distance by rail, but might have gone
by ship to either New Orleans or even around the Horn before being loaded
onto freight cars.

Tim O'Connor

I don't believe the Central Valley truss bridge is a pin-connected truss bridge. A model image is on their mainpage: http://www.cvmw.com/
I'm more familiar with a pin-connected truss looking more like this one. Note the steel members along the bottom outide of hte truss.
http://www.texnrails.com/catalog/details.asp?sid=JF25697055421821&mfg=TMS&item=2200301&cat=&series=
Of course, material for either type of bridge most likely was transported in steam era freight cars to the building location.
Eric

[Non-text portions of this message have been removed]



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[Non-text portions of this message have been removed]

Fred,

From Wikipedia, citing Tom Daspit. "The Days They Changed the Gauge" . http://southern.railfan.net/ties/1966/66-8/gauge.html . Retrieved 2008-12-28 .
Gauge


The Panama Railway was originally 5 ft (1,524 mm) gauge. The gauge was changed only in 2000 to 4 ft 8 + 1 ⁄ 2 in (1,435 mm) so as to use standard gauge equipment. The original gauge was chosen under the influence of the pre-conversion southern United States railway companies, which converted in May 1886 after the American Civil War . [ 13 ]
Ken Montero

I'm interested in patching and fine scale chain. I'm NOT interested
in bridges, and even less interested in the Panama Railroad. How
about changing the subject line, guys?

Richard Hendrickson

Hi Fred,

The PRR had a gauge of 5'-0". All of 47.5 miles long. The first transcontinental railroad. Built in 1855. At the cost of about 10,000 lives. The Panama jungle is a tough place to build and run a railroad.

Today's railroad while related to the Panama RR is now standard gauge and follows the new alignment and route that was built at the time of the American Era during the construction of the Panama Canal. Most of the older right of way is now under water.

Cheers,
Bill Keene
Irvine, CA


On Jun 11, 2010, at 5:56 PM, Frederick Freitas wrote:

Hi Bill,

The Panama RR, was it standard, or narrow ga. ?
If narrow, you know there will be a car so lettered on a
PRR flat headed to a shipping point.

Fred Freitas
admitted SPF

________________________________
From: William Keene <wakeene@...>
To: STMFC@...
Sent: Fri, June 11, 2010 5:40:46 PM
Subject: Re: [STMFC] Re: PATCHING, and fine scale chain

Hi Tim & Group,

I think that the bridge dates from the early 20th Century... something like 1902, I think. In this case you have the correct idea. But I would guess that it is more likely that it was shipped by rail instead of going around the tip of South America.

But there is a third route... by ship to Colon, Panama, Colombia (remember that Panama was a state of Colombia at the time), then transshipped over the Panama Rail Road (PRR... just love those initials), and then transshipped again up the west coast with the final delivery being by rail. Most likely still faster than going the extra miles around South America.

Cheers,
Bill Keene
Irvine, CA

On Jun 11, 2010, at 2:16 PM, Tim O'Connor wrote:

Eric is correct -- this is the Central Valley prototype in Piru, CA
http://www.bing.com/maps/?v=2&cp=pr2gdb530vcq&scene=11424394&lvl=2&sty=o

The CV web site says the bridge was built by the New York Bridge Co. It
was no doubt shipped in pieces some distance by rail, but might have gone
by ship to either New Orleans or even around the Horn before being loaded
onto freight cars.

Tim O'Connor

I don't believe the Central Valley truss bridge is a pin-connected truss bridge. A model image is on their mainpage: http://www.cvmw.com/
I'm more familiar with a pin-connected truss looking more like this one. Note the steel members along the bottom outide of hte truss.
http://www.texnrails.com/catalog/details.asp?sid=JF25697055421821&mfg=TMS&item=2200301&cat=&series=
Of course, material for either type of bridge most likely was transported in steam era freight cars to the building location.
Eric

------------------------------------

Yahoo! Groups Links

[Non-text portions of this message have been removed]

[Non-text portions of this message have been removed]