611 engine truck rebuild

lady611 · **Joined:** Tue Jun 04, 2013 4:28 pm **Posts:** 54

I have recently received the news from the VMT that there is a redesign in progress of the engine truck on 611. It was my original understanding that the engine truck wheels needed to be replaced, as that was something that was planned to be done when the original NS steam program shut down in 1994. Do any of you know why a redesign/rebuild of 611's engine truck might be necessary?
lois

whodom · **Posted:** Sat Mar 15, 2014 8:02 am

lady611 wrote:

I have recently received the news from the VMT that there is a redesign in progress of the engine truck on 611. It was my original understanding that the engine truck wheels needed to be replaced, as that was something that was planned to be done when the original NS steam program shut down in 1994. Do any of you know why a redesign/rebuild of 611's engine truck might be necessary?
lois

Lois- I read something that said the engine truck axle bearings also require replacement and these bearings are no longer available, so the truck is being re-worked to accept new off-the-shelf roller bearings.

They ran into a similar issue with the roller bearings for the rods many years ago. Timken assisted in the design of "adapters" that allowed new off-the-shelf roller bearings to be installed without modifications to the rods or crank pins.

dinwitty · **Joined:** Wed Oct 22, 2008 8:18 pm **Posts:** 2226

they may do some cutting/welding/fitting for the new parts on the original assembly to make it work.

NKP 765 tender trucks were friction bearing, but they decided to adapt them to roller bearings but kept the friction bearing "cups" in place to keep its original look. Right now the rear trucks are still friction bearings. (on the engine) (unless they changed that already I don't know)

Emmo213 · **Posted:** Sat Mar 15, 2014 10:38 pm

Here is the information VMT sent out to everybody.

Quote:

It's no surprise that 611's front engine truck wheels (the leading or first 4 wheels of the locomotive) are due for replacement. The work on the Class J 611's truck wheels was scheduled in 1994, but instead, NS' steam excursion program ended, and the locomotive returned to her home at the Virginia Museum of Transportation in Roanoke.

Fire Up 611! mechanical team members Scott Lindsay and Bob Saxtan have been working on a plan to replace the front engine truck with new wheels, axles and roller bearings that are available today. Mechanical engineers are looking at replacements that will properly support and guide the locomotive. Those same mechanical engineers will design a bearing box that will adapt the axles and bearings to the existing truck frame.

GaryPBensman · **Joined:** Sun Oct 20, 2013 8:12 pm **Posts:** 18

Just as has been done in the past on Frisco 1522 and SP4449. (Both with 4 wheel engine trucks) And is also presently being worked out for B&M #3713 at Steamtown.
The trick is finding the correct profile of wheel plate so all the fit and lateral works as designed. We who are working on the 3713 are also working with the 611 men to see if 8 wheels might be cheaper than 4 wheels twice.

lady611 · **Joined:** Tue Jun 04, 2013 4:28 pm **Posts:** 54

A kind thank you to all of you for your replies. Now I am able to understand what will be going on during the redesign of 611's engine truck. This appears to be an important factor in the restoration so I wanted to know the details of what was going on.
lois

TimReynolds · **Joined:** Sat Aug 31, 2013 4:11 pm **Posts:** 287

I see looking back through photos that the engine trucks had solid wheels instead of the spoked ones. Did 611's lead engine truck ever have the spoked ones or were spoked wheels only on the earlier locos in the class?

lady611 · **Joined:** Tue Jun 04, 2013 4:28 pm **Posts:** 54

611 always had solid engine truck wheels, as referenced by the photos I have of her first day out of Roanoke Shops on May 29, 1950.
lois

Emmo213 · **Posted:** Tue Mar 18, 2014 1:46 pm

611 has always had some form of solid wheels on her engine trucks.

The first 11 Js were built with spoke engine trucks, which were then replaced starting in 1948 with rolled steel wheels (this is what 611 started with). Starting in 1953 those rolled steel wheels were then replaced with cast steel wheels.

Overmod · **Joined:** Thu May 24, 2012 1:37 pm **Posts:** 2492

The single rods were a 'retrofit' intended to solve chronic fracturing pins on the #4 driver pair. They were only applied when a locomotive needed significant rod work -- ISTR 611 got her 'kit' after the Tug Fork derailment...

The 'new' rod arrangement isn't as high-speed optimized as the original tandem setup... but it should be somewhat more tolerant of high piston thrust.

lady611 · **Joined:** Tue Jun 04, 2013 4:28 pm **Posts:** 54

611 got the single rods after the derailment, but as far as I know, not as a result of the derailment. The only damage involving rods from this wreck was on the fireman's side, and that may only have been the eccentric and main rod stripped away with the valve gear, some portion of the cylinder, the running board, turbogenerator and other appliances on that side. Since I have only what was in the wreck reportsand have never seen a picture of the damage from the wreck (that is, if one even exists)I am limited in what can be reported on said damage. The damage stated would have been from the locomotive sliding on her side during the wreck, occuring after a leap over the outside rails of the double track mainline, resulting from derailing on a sharp curve at speed.
lois

whodom · **Posted:** Tue Mar 18, 2014 9:25 pm

Well, it would make sense to update the rod arrangement as long as you had to replace the main rod anyway.

Interesting to know the true cause of this program. IIRC, Miller's book on the J's (or possibly Jeffries' book on N&W steam) said the rod change was to allow a larger big end bearing on the main rod as these were rarely known to seize.

I suppose it's possible that both reasons led to the rod replacements, but the long, somewhat spindly #4 crankpin required by the duplex rod arrangement does seem a little more plausible as the culprit.

Wowak · **Posted:** Wed Mar 19, 2014 4:19 am

Reading and Northern #425 just had a completely new lead truck installed, I believe it was built at Strasburg.

SteamPWR · **Joined:** Sun Dec 30, 2007 6:01 pm **Posts:** 52

The wheel, axle, bearing and bearing box work was done by Strasburg. The rest of the work was done by McAdoo Machine and in house at the R&N. A new set of drawings was made before any work started. The entire truck is 95% new.

TimReynolds · **Joined:** Sat Aug 31, 2013 4:11 pm **Posts:** 287

R&N 425's new engine truck can be seen here
http://www.rypn.org/forums/viewtopic.php?f=1&t=35362&p=200098&hilit=425#p200098