Split chassis

[Trains trains trains]

Hello, I am wanting to buy the early Hornby School class locomotive Stow, and was just wondering, in the advertisement it says a split chassis. What is a split chassi ? I have no intention to convert to dc so what are the possible downsides ( if any). Any help would be greatly appreciated.

[96RAF]

An early way of passing power from the rails to the motor was by making the chessis in two halves  with an insulator inbetween and letting the chassis transfer the power to the motor rather than use wires. There is no disadvantage when using these models on DC, in fact they can be very reliable.

 

The problems come when converting to DCC as you have to isolate the motor from the power pickup and with some of these chassis it can be very difficult. However as you are sticking with DC it will not be your problem.

[atom3624]

Did Hornby ever do this - I thought it was Bachmann?

 

Al.

[Ruffnut Thorston]

With Hornby models, usually the term split chassis refers to having a cast chassis block, and a plastic bottom plate, wheel retainer, that clips, and or screws, to the metal block.

 

The original Hornby King, and all of the 1981 introduced 4-4-0 locos, including the Schools Class are examples of this.

 

Service Sheets.

Note that the later model has the chassis block as part of the pick up. The insulated wheels on the later models are in the other side from the original models, which have wiper pick ups insulated from the chassis block.

 

 

Also, the original locos have the front bogie as part of the pick up, with metal wheels on the same side as the wiper pick ups.

 

The later model does not use the front bogie for pick up.

 

/media/tinymce_upload/24081fc91f9c77b2e17da53b1d317dae.jpg

/media/tinymce_upload/a04959492666ac50a94c19b9e0a33749.jpg

 /media/tinymce_upload/6b9f6fe4cd839481a351f60677b99df5.jpg/media/tinymce_upload/5313f0278c4a4ee8eeadfc21f90fba19.jpg

 

As far as I know, the only true  electrically split chassis "Hornby" models were the original Tri-ang Railways "Rocket", and the Battle Space Turbo Car, with its propeller drive.

[ColinB]

I have one of these I bought in the eighties, having converted a lot of "split chassis" Bachmann A4s, these are definitely not the same. I assume by split chassis they mean the loco chassis picks up one side of the supply and the tender picks up the other. So I assume they really mean split supply. The original ones had a smoke unit, although it is a good idea to remove it before it warps the loco body ( as it partially did with mine ). If you are into soldering they are really easy to upgrade to DCC. Fortunately, Hornby used pickups on this model to collect the power, on others it used the axles, so by adding a connection to the loco chassis you can now pickup power in the loco on both wheels, which gives a great improvement on running. Connect it to the tender and you have a really good runner.

[Ruffnut Thorston]

@ColinB.

 

The earlier models did indeed have the "sword" type pick ups.

 

The later models, however, did away with the wiper pick ups, possibly to reduce drag on the unpowered wheels, using the wheels, axles, and chassis block to conduct the power to the drawbar and Tender.

 

The one wire on the later locos (see Service Sheet above) connects the chassis block to the drawbar, which retains the insulated plastic mounting.

 

It would be possible to reconfigure a later locomotive, if you can get the spare "sword" pick ups.

 

The wheelsets would need to be turned around, so that the insulated wheels were on the pick up side.

 

Wiring would need to be arranged, soldered to the pick ups, to take the power to the insulated drawbar, in place of the long bridge wire in the later locos.

 

The plastic baseplate on the later tender drive locos retains the mountings for the sword pick ups.

 

As the later locos use insulated bogie wheels on both sides, it isn't necessary to connect the bogie frame to the wiring.

 

As far as I know, "split chassis" in Hornby models does refer to the split between metal chassis block and plastic base plate/ wheel retainer.

[ColinB]

My Stowe was the early type, but I know what you mean about the sword type pickups, they used the same system in the A3s. Before I sold them I did contenplate converting them to dual pickups, Lendons still had some in stock, but I decided I would rather have a loco driven one, the eight wheeled tenders don't seem to drive as well as the 6 wheeled ones.

[Ruffnut Thorston]

The 8 wheel LNER type tenders have the weight spread onto the rear wheels, which are a separate pony truck, and so are not as well balanced as the 6 wheel tenders.

 

So there is not so much weight on the driven wheels, as in the 6 wheel tenders.