Tender Drives

[R.K. Maroon]

A friend of mine has a scratch-built locomotive that was designed to have a tender drive. To me this usually means that the motor is in the tender with a shaft to a gearbox on the engine drivers. However, in this case, the engine has no gearbox. The tender is designed to have gearboxes on the axles -- essentially like a short switch engine. However, the drive was never installed, as my friend put it on his mantel (and eventually on his layout) as a display model. Does anybody have any history with this type of setup? One would have to weight the tender for it to pull anything, but I can't think of an obvious reason why this would not be an acceptable setup.

Jim

[ScaleCraft]

Only one I can think of off-hand is a Tyco Chattanooga Choo-Choo in Half-Zero scale.
First is, never any driver slip starting heavy loads. Looks funny when you hear wheels slipping and nothing visible IS.
Lead driver being pushed along in that instance was a problem...without power it seemed to have a propensity to climb rails.
Noise.
Depending on what the tender shell is constructed OF, more motor noise than you'd get with motor and gearbox hidden inside a heavy, noise-attenuating boiler.

Almost sounds like a candidate for some kind of drive like the old NWSL Flea drive.
With kingpins closer together than most diesel switchers, would be different.

[bob turner]

Probably not a great idea - but consider the Diesel situation - you can have a powered B and a dummy A - I submit that it will be the same as a powered A dummy B in performance.

Additional advantage for some is no visible gearbox between boiler and frame.

The AN Articulated had one powered engine and one dummy. With all that weight it could barely pull itself around my loop.

[ScaleCraft]

And tender drive eliminates the bugaboo of tender motor engine drive.
Opposing Torque.

Load it up starting a big train, tender torques one way, engine the other, and it is usually obvious.

[Chris Webster]

Does anybody have any history with this type of setup? One would have to weight the tender for it to pull anything, but I can't think of an obvious reason why this would not be an acceptable setup.

I used to run trains on a German-prototype HO layout back when I was a teenager. The owner had several locomotives that were tender-driven. Their drivers would frequently stop turning and just slide along the rails as the engine was pushed by the tender.

[Bob Anson]

Lou Ertz had a tender drive model if memory is right it was a Milwaukee Road atlantic that was either redone by Jerry White or Stu Klienschmidt. ran smoooothe .
Bob Anson

[Bob Anson]

Just double checked Lou's inventory list and it was Jerry White and not Stu.
Bob

[E7]

SMR did a bunch of tender drives in their 4-4-0's. Seems to me that I read where more recent stuff is in the boilers! I am thinking smaller size motors, but I don't follow them that closely.

[Robert]

When I think of tender driven locomotives...I envision a motor in the tender suitably connected to a gearbox in the boiler. My Jerry White configured D16 is so arranged, and is a remarkable running piece obviously due to Jerry's mechanical excellence. The one Jim started this thread with seems a real oddity at best with everything, drive included, located in the tender. A photo of it would be interesting.

Robert

[Bob Anson]

Lou's was tender drive no gearbox in loco. I remember this because it was chain drive and was HEAVY.
Bob

[jwmathews]

Haven't viewed this form in several weeks & just spotted this thread.

The SMR models of the 1860s-era locos use powered tenders, which is probably a more accurate description than "tender drive" (meaning motor in tender driving a shaft forward, connecting to shaft & gears in the loco via a U-joint between loco & tender). Now with the nomenclature explained, the SMR locos I've seen are the 4-4-0 and 0-8-0 Winans Camel models with very small boilers, as made to proper scale proportions. Not enough room inside for a motor of sufficient power. The tenders are also small, but cam be heavy enough to pull small, lightweight cars. The tender trucks are geared like diesel power trucks, and are small enough that HO-size gearboxes will fit and are adequate to do the job.

The 1970s AHM Rivarossi imports such as the Casey Jones 4-6-0, V&T 4-4-0s and the IHB 0-8-0 were plastic models of relatively light weight. While motorizing kits were offered, they did not have hi-grade components and were not as numerous as were the loco kits. Powered tenders might be a way to use some of these models on a layout. (Just an idea.) A late friend of mine had one of the 0-8-0 models, which featured a booster truck (with side rods) under the tender. He powered that booster with one of the NWSL axle-mounted motor/gear units & it was interesting to see the tender move by itself. There was a speed difference with the tender being faster than the loco & spinning its wheels, which tended to spoil the effect. There are probably ways to correct that disparity (voltage drop devices to the tender motor, perhaps?), but I don't recall my friend ever fixing that._