Doodlebug (Walther / Spectrum)

I have a Bachman Spectrum version, in Boston & Maine colors.

It scales out to about 85 feet in lrength. In metric terms, a full size one would be about 25.9 meters. The Bachmann unit is relatively long.

Mine runs well.

I am not entirely pleased with the appearance. It "looks" odd with that length on my layout. Just a personal preference thing.

The Walthers unit is about 60 scale feet long, or about 18.2 meters. I do not have one of these. I do not personally know how well the Walthers unit runs.

I once read an on line report about the Walthers unit which criticised the power / drive unit in the Walthers unit.

Since I do not have a Walthers unit I cannot personally comment upon the qualities of the Walthers unit.

I do not know first manufacture date of either the model or prototype for either the Bachmann or Walthers unit.

Please do not worry about your English. Your command of Englih is far better than my command of German.

-- Jim McLaughlin

Please don't just hit the reply key. Remove the obvious from the address to reply.

Thank you Jim I habe 2 x the Bachmann Version Run good, after i solder new the electric wires to the the weels I buy just today the walther version by ebay for $20 New I think it?s fair price. i wait of incoming I search more for prototype information of the doodlebugs and i search for DCC decoder built in information for Walthers greetings Juergen

I have the Walthers, Juergen, but haven't run it much. So far, it's very smooth and quiet running, but in my mind, could use more weight, it's very light. Running as the prototype would, that being with only one or two cars, and usually none, behind it, it should be fine as it is. Speeds seem to be well with in a realistic range.

Greybeard

I have the Bachmann Spectrum. Runs ok. Does not start well though. It takes about 6.5 volts before it starts to move. I have two of them and they run about the same. A friend has the Walthers and his does run a little bit smoother. Needs more weight though.

ChrisGW

According to the June 2002 Railroad Model Craftsman review, [page 100] by Trevor Marshall, the Walthers product is of a 1923 B&M prototype with a St. Louis Car Co. body.

According to the June 1997 Model Railroader review [page 32] The Bachmann product has no prototype but is based on EMC late 20s practices. The problem is that EMC basically just supplied the mechanicals and the actual carbody was built by any one of several passenger car manufacturers. The most common being Pullman or St. Louis Car Co.

To many people being a model of a actual prototype makes it better.

The drivetrain of the models are roughly equal. They're both single truck powered. The Walthers unit has a can motor and a flywheel so it probably performs a bit better.

The Bachmann is cheaper and more conductive to being kitbashed into something more prototypical.

Eric

J=FCrgen Pollak wrote:

"Which is the difference between the Bachmann Spectrum and the Walthers EMC Gas Electric Doodlebugs?

According to the June 2002 Railroad Model Craftsman review, [page 100] by Trevor Marshall, the Walthers product is of a 1923 B&M prototype with a St. Louis Car Co. body.

According to the June 1997 Model Railroader review [page 32] The Bachmann product has no prototype but is based on EMC late 20s practices. The problem is that EMC basically just supplied the mechanicals and the actual carbody was built by any one of several passenger car manufacturers. The most common being Pullman or St. Louis Car Co.

To many people being a model of a actual prototype makes it better.

The drivetrain of the models are roughly equal. They're both single truck powered. The Walthers unit has a can motor and a flywheel so it probably performs a bit better.

The Bachmann is cheaper and more conductive to being kitbashed into something more prototypical.

Eric

J=FCrgen Pollak wrote:

"Which is the difference between the Bachmann Spectrum and the Walthers EMC Gas Electric Doodlebugs?

schrieb im Newsbeitrag Thank you all for the information This help Juergen

Just for the record, the vast majority of real 'doodlebugs' were only powered on one truck also. They could usually pull one trailer car.

A few doodlebugs had both trucks powered, and could pull a small train of several coaches or perhaps 15 freight cars. Such machines were used as branch line locomotives, often on mixed trains (freight and passenger cars in the same train).

Dan Mitchell ============

I have a couple of both makes. The Bachmann drive is geared, and can be rather noisy. I removed a few bits and bobs from the drive and glazing so that they no longer touched, and this helped reduce the noise by minimising the tendency for the body to vibrate and buzz.

The Walthers drive incorporates a small rubber belt - an "O" ring by the look of it - on the flywheel, so it is fairly quiet, but on both examples I have the belt broke soon after purchase. In both cases there was a spot of excess glue used to attach the glazing on the belt at the point it broke. I suspect it caused to the rubber to harden or otherwise deteriorate. I replaced them with an "O" ring sourced from my local plumbing supply, and have had no trouble since.

"Just for the record, the vast majority of real 'doodlebugs' were only powered on one truck also. They could usually pull one trail er car.

A few doodlebugs had both trucks powered, and could pull a s mall train of several coaches or perhaps 15 freight cars. Such machines were used as branch line locomotives, often on mixed trains (freight a nd passenger cars in the same train)."

Physics dictate that a 70 ton 1:1 scale doodlebug has much better traction than a 1:87 one. A model train really needs all dual truck all wheel pickup. That would get in the way of the nifty interior details.

Pers "I have a couple of both makes. The Bachmann drive is geared, and can be rather noisy. I removed a few bits and bobs from the drive a nd glazing so that they no longer touched, and this helped reduce the n oise by minimising the tendency for the body to vibrate and buzz."

Well, Bachmann has never been known for it's quality control. There is no such beast as ready to run.

"The Walthers drive incorporates a small rubber belt - an "O" ring by the look of it on the flywheel, so it is fairly quiet, but on both examples I have the belt broke soon after purchase. In both cases there was a spot of excess glue used to attach the glazing on the belt at the point it broke. I suspect it caused to the rubber to harden or otherwise deteriorate. I replaced them with n "O" ring sourced from m y local plumbing supply, and have had no trouble since."

What diameter o-ring are you using? This sounds like an upgrade that one ought to do right after opening the box. Eric

What HO models would make appropriate "coach seating only" "trailers" for each of the @ 85 foot Bachmann Spectrum doodlebug and the @ 60 foot Walthers doodlebug?

It depends on what RR and what period you are modeling. It would be an older day coach of the style that was plentiful on the particular RR. If you're modeling the 1930's and into WWII, it might have been an old wooden car. On the Erie, it'd be a Stillwell coach. On the UP or SP, it'd be a Harriman arch roof car. On the C&NW, it might be one of the 60' commuter coaches by Rivarossi and recently reissued by Walthers. On the Pennsy, an un-modernized P-70, etc. etc.

However, both the Walthers and the Bachman gas-electrics have fairly large coach sections. From the pictures I've seen, it would be more typical for these type cars to be hauling an extra baggage car to give more room for the branch line's LCL freight. Gas-electrics that were all baggage, or all baggage/RPO, or with only a 4 or 5 window coach section, would be more likely to be hauling the extra passenger coach. This is not a rule, but a trend in old doodlebug pix. Gary Q

Actually, physics does *NOT* dictate any such thing. Both real and prototype railway locos have roughly the SAME potential pulling power. Pulling power ("Tractive effort") is the locos's weight on drivers times the coefficient of friction (roughly the "factor of adhesion"). This is true for both prototype and model. All else being equal, the DENSITY of a model is the same as it's prototype. Thus it inherently has 'scale weight', and scale tractive effort.

The differences arise in that our models do NOT have "all else being equal" ... they are not made of thin hollow shells of steel, but rather blocks of solid diecast metal (frames, weights, power trucks), relatively HUGE and nearly solid motors, and some thin plastic parts. Overall, thay are usually far closer to 'solid' than a prototype loco. Thus, they are actually MORE dense than scale, and hence often heavier than scale ... this SHOULD give them MORE than scale tractive effort. That is compensated for by the 'coefficient of friction' issue. Real railroads are almost always 'steel wheel on steel rail. .. this give a friction coefficient of about 25%. Model wheels are usually brass or nickel silver wheels on brass or nickel silver track. This gives more like 18%-20% friction, so the model gets less 'traction' for a given weight.

often remarkably close to 'scale'. This does **NOT** take into account any 'traction tires' that greatly increase the friction and increase tractive effort WAY beyond scale values.

Even that is compensated for to varying degrees by the fact that our model cars have a LOT more rolling friction than real train cars. THAT (together with our often excessively steep grades) is why we often can't pull nearly a scale length train.

And that's why I stated in a recent earlier post that "If you want to pull long trains, you should spend a **LOT** more time reducing your rolling stock's friction (metal wheels, better trucks, etc.) than worrying about increasing your locomotive's pulling power."

Dan Mitchell ============

Nobody makes a true 'doodlebug trailer' coach (except in brass), but doodlebugs often just pulled any old coach that was available, especially the smaller and lighter varieties. You often saw them with both wooden and steel 60-70 ft. 4-axle coaches of every description. The recent Rivarossi 60 ft. C&NW coach would be a good freelance choice.

Dan Mitchell ============

Good point!

Dan Mitchell ============

often heavier than scale ...

I don't think so. A 150 ton prototype loco would weigh 3448 actual pounds in HO. (150 tons divided by 87, then times 2000 to convert tons to pounds).

Your point about traction tires is well taken, though.

Walt

Mass is a volume property and not a length property, so it follows the cube of the scale factor. You need to divide by 87 x 87 x 87 !! Gary Q

And thus, a pound of hydrogen and a pound of plutonium always occupy the same volume.

snipped-for-privacy@pimin.rockhead.com (Paul Newhouse) wrote in news: snipped-for-privacy@comcast.com:

I wasn't going to jump into this, but...

Mass is a property of things that HAVE volume, but not directly related TO their volume. A kilo of hydrogen and a kilo of plutonium certainly don't have the same volume. (Technically, the pound is not a measure of mass, since it assumes measurement under one standard gravity. I'd only weigh 44 lbs on the moon! A kilo is a kilo no matter where you take it.) Mass being a property of things that have volume, and volume implying three dimensions, mean his calculation is right, but for the wrong reason.