To be restored at Tennessee Valley Railroad Museum? Anybody at TVRM care to comment?

Frederick G. Bailey

Well that is very good news. More Steam power being brought back to the rails is a sight everyone wants to see.

576 is a nice looking locomotive, and the shelter in Centennial Park is top notch. I've been down there to see her a couple times since I moved to Nashville.

Well, whoever wrote the announcement obviously knows little about steam locomotives and curves unless there was a typo. I suppose a shay or an 0-4-0 could go around a 30' curve, but a 4-8-4? Not possible! (Well, at least not a full size 4-8-4). I'll have to do a little digging but 15' or 16' is likely the max. The lateral motion devices can help, but there is this thing called a stoker that would prohibit negotiating such a curve. 4501 (still hand fired) can go around relatively tight bends, but getting up around 19' or 20' puts the tender and cab so close the grab irons nearly touch. In fact, I'm not even so sure that diseasals (4 or 6 axles) could make such a tight curve.

As for the q about TCRM's train, they have a beautiful all stainless consist (mostly or possibly all Budd cars, IIRC) that they regularly use on their excursions. Check out their website for photos.

576 is the only standard guage NC&StL locomotive extant as I recall, but there are/were two little narrow gauge locos privately owned near Tracy City, TN.

I'd love to see Dixie rising, but I am very skeptical of this. The locomotive is certainly very restorable. The best part is that, except for vandalism to the guages, she is equipped, not stripped. The biggest concern and unknown would be the condition of the boiler underneath the jacket with respect to corrosion. As she is a fairly modern locomotive, I suspect the steel will be relatively easy to make weld repairs should they be needed. As for the frame, any problems that might encountered should prove very repairable, though I seriously doubt major concerns.

It is fun to think about 576 in the shop at Chattanooga, but don't waste too much time daydreaming.

Best,
Mike

Ready fire aim... Has anybody thought about the fine stainless train of heritage cars the TC Museum routinely runs on their excursions? They have 2 HEP making baggage/rpo cars I don't know if the stam engine is going to be restored, but It's a sure bet that there's a train for it to pull, if it is, and it is right in Nashville it isn't bi-level.

See http://www.tcrm.org

To quote their equpment page:
The TC Railway Museum takes great pride in our excursion equipment. Our typical excursion train has a capacity of approximately 400 passengers, carried in air-conditioned streamlined stainless steel equipment. Our cars are equipped with Amtrak-compatible Head End Power (HEP), and the museum owns two 480 volt power cars. The Museum's buffet lounge and dining cars haves facilities for preparing everything from snacks to complete meals, and our slumbercoach contains private sleeping accommodations for up to 42 people on overnight trips. The train includes a concessions car complete with gift shop. The museum also has access to additional privately owned equipment including dome, buffet-lounge, and office cars. Excursion trains are typically pulled by vintage F7 and E8 diesel locomotives.

G.F.Payne
Baltimore.

i would assume you mean this site: http://tcry.org/

What if there was no stoker because it's was converted to oil for the restoration?

BLASPHEMER!

Seriously, it makes little or no difference. The trailing and lead trucks can only move so far and the close coupling of the tender to the locomotive prohibit movement around very sharp curves. The maximum curvature could be determined by the rigid wheel base or problems with the stoker delivery tube and screw. Once you get to a certain point, the rigid wheel base will cause the locomotive to climb the rail or turn it over and choo-choos don't run so well on crossties.

Mike

On the topic of curves, I'm pretty sure NKP #765 was designed so that a 20 degree curve is possible, I think I've been told by people involved that they had to fold up the tender deck plate to do this.

On the diesels, probably not the recommended daily kind of thing, but they published these numbers.

From the GM manuals:

E-9 Minimum Curve Radius 274' (21 deg)

SD-45 Minimum Curve Radius
Single Unit ..................... 193'
Coupled To Standard 50 Ft. Car .. 338 deg

F-7 Minimum Curve Radius 250'

F-40 Curve Negotiation Capability:

Truck swing limits single unit curve negotiation to a
43 deg 30' or 135 ft. radius curve.
Two similar units coupled in multiple limited by
coupler swing to a 33 deg or 175 ft. radius curve
(equipped with "F" couplers).
Locomotive coupled to an 89 ft. passenger car
limited by car coupler swing to a 18 deg or 315 ft.
radius curve (equipped with "F" coupler).
Locomotive coupled to a standard 50 ft. box car
limited by car coupler swing to a 23 deg or 250 ft.
radius curve.

GP-9 Minimum Curve Radius Coupled To Car 150' (390)
Minimum Coupled To Another Locomotive Of
Same Type With Type "E" Coupling 274' (210)

GP-38 Minimum Curve Single 140'
Coupled to 50' Car 302'


....and the Alco Manuals say:

C420 & C424 MU Operation 30 deg
Single Unit Without Train 39 deg

C628 MU Operation 21 deg
Single Unit Without Train25 deg

RS1 100' (Hard to believe)

Thinking of tight museum curved tracks, how tight do they get? Anyone know what the wye at TVRM is in terms of curvature?

David Farlow
Whitewater Valley Railroad

Maximum curvature for steam locomotives depends primarily on rigid wheelbase. You can gain a little more with reduced flange back to back spacing on the first and last driver and, of course, you can also resort to blind center drivers. Later engines often had lateral motion devices.

As a general rule, the maxium curve for large 8 coupled engines is between 16 and 20 degrees. Engines with lateral motion devices on the lead driver tend toward the latter. 1225 with 69" drivers and a lateral motion device could get around curves that PM's smaller drivered mikados could not precisely because of its lateral motion device.

That being said, you still need to be careful on such curves. There is a curve in Owosso on the Chesaning branch (ex-MC to Saginaw) that reaches 19 degrees and is superelevated. When we went through there the first time we oiled the rail. The unexpected result was the locomotive slide down the superelevation and bore so hard on the inside of the main and intermediate flanges that the main and intermediate drivers lifted on the outside of the curve. We don't oil curves anymore!

Andrew Adams

The East leg of the wye at Grand Jct is approximately 17'. I think Track 7 going into the shop has the sharpest curve just past the 7-8 switch, though this could be from a lack of spiral leading into the curve. I know 4501's pony truck will lift off the inside rail a few inches when it negotiates the curve on Track 7, but has never derailed as far as I know.

I am actually quite surprised that maximum curvature is so high for some of the four axle units, though the coupled number is the only really practical application of the maximums.

I seem to recall a discussion at an RPCA meeting some years ago about the maximum curvature that various big locos could negotiate. IIRC, various engines running at the time were discussed among the operators and included 611, 844, 261, and possibly 765. 611 was somewhere around 14'. I don't recall exactly what the other were, but 14-16' seems familiar. Obviously 765 was a bit more. Interestingly, the stiffening of the N&W J's lead and trailing trucks is what keeps the maximum curvature relatively broad considering the ridgid wheel base of drivers is considerably less than, say, 844 or 4449.

On another interesting note, the south leg of the wye at the former CofGA Industry Yard at East Point, GA (the East end of the A&WP) is so sharp that the Mark IV and later Roadrailers will not negotiate it without crushing the corners of the trailers, but I've turned MU'd six-axle power there many times.

Mike

There are 29 and 33 degree curves on the old Western Maryland (now West Virginia Central) line from Elkins to Bergoo, WV. 4-axle power was used to operate unit coal trains on the line. The WVC operates a passenger train through it using short cars and Fs, Geeps, or a BL2 for power. I've heard that the 33 degree curve (176' radius) was the sharpest "mainline" curve around, but don't have proof. According to the data posted by David Farlow and from what I have seen, this is close to or beyond the theoretical coupler swing limits. Anyone know specifics about the passenger cars used by WVC?

I did a little more digging on 576. The J-2 Dixie is the second lightest North American 4-8-4 existant and the lightest in the US. (I'm not counting the South African Cape guage and don't know if there are any European or Asian 4-8-4's. Russia, India, China?) Only the CN U-4a in the Museum at Ottawa is lighter. The FCdeM Niagra is just a little heavier and has higher boiler pressure. The Dixie has lateral motion devices on the first two axles so it probably can do better than 20 degrees, but I still doubt the 30 degree claim. I'm still looking for a diagram with official information.

Andrew Adams

OK, I screwed up. 576 is a J-3 not a J-2. Like most WWII built engines, it weighs more than its pre-war predecessors. It is not the lightest 4-8-4 in the US. The www.nctsl.com/576/index.html website has an article that claims only one lateral motion device and a 20 degree curve limit.

The engine is still on the small end for mainline excursion engines with only 57000 lbs of tractive effort and a tender capacity of 16 tons and 15000 gallons. Makes for more refueling logistics on longer runs. I also suspect finding an auxiliary tender is getting difficult these days.

Not to be negative, but after doing this stuff for a while, the practical considerations always pop up first. Mark Twain once commented that after piloting a river boat on the Mississippi, he couldn't watch a sunset over the river without worrying about bars and snags.

Andrew Adams

Do a 614 and turn the tender into fuel only with an aux for water. I would imagine the building of an AUX tender would not be that hard. Maybe base it off a tank car?