Ob from a Frateschi Baldwin 2-8-0

or. . . Yet another diversion. Again.


Ob Class steam locomotive, WMR 11, 2-8-0 type (later NZR 'Ob' class 455).. Godber, Albert Percy, 1875-1949 :Collection of albums, prints and negatives. Ref: PA1-q-101-038-1. Alexander Turnbull Library, Wellington, New Zealand. http://natlib.govt.nz/records/22874474

Never been a fan of hissy things. Growing up in the Wellington region I never saw them, and my only close encounter was with Ja1278 while on a visit to Frankton Junction in1967 where I was shown around the cab. And even that never did anything for me - was more interested in watching a Dsc shunting at the time!

But must admit the old Baldwins in NZGR and WMR service are really growing on me.

I lay the blame with Wayne Haste's February 1998 Model Railway Journal article on how he had made one of the little Frateschi cuties into an NZR T class for Sn3.5.

Plus I recently inherited a rather nice collection of Steam in NZ books. And the more I browse . . . Oh dear.

So a rush-of-blood TradeMe purchase of a Frateschi 2-8-0 means another project gets added to the list.



Frateschi 2-8-0 out of the box - has to become an NZGR Baldwin!


Although it doesn't fit my era (all gone by 1931) and none have been restored, the old modellers'
license comes in to play. viz. There will be a guest appearance of a Rimutaka Incline Railway restored Ob with attendant 47ft woodies (or some L, M, and U class wagons). The original loco was rescued from the bush at the old Summit Station site :-)


How does it measure up?
If wanting to emulate Wayne Haste's conversion, there is no way this could become a T class in OO scale - even without measuring up - the driver wheels look way too big.

So after checking against CGL drawings, the Ob class was a closest match for looks and for OO scale.

Without rivet counting, you could just paint this overall grubby black with red headstocks, add some number plates and it would pass as an OO scale NZGR Ob class - ex-Wellington and Manawatu Railway numbers 11 and 12.


But for just a a little more accuracy . . . without going too overboard. . .

The Ob has uneven driver axle spacing with a larger gap between the middle pair, while this Frateschi model Baldwin has even spacing and would be difficult to fix.

A saving grace is that the overall spacing front to rear axles is 49mm, spot on for OO scale. Shame really because the uneven spacing is a characteristic "feature" of the Ob.

Driver wheel size is spot on at a smidgen over 14mm, while the front truck spoked wheels are a smidgen under 10mm where they should be 10, so un-noticeable.

The main cylinders, valve gear, and con rods are reasonably accurate according to drawings and photos.

The cab is a couple of mm too long and too short in height so will need "adjusting", as do the windows. The Frateschi has one small and one large side windows, while the Ob has two same-sized.

Then the whole cab needs shifting 6 or 7mm rearwards, and with that, magically the boiler protrudes into the cab the exact, correct amount.

Boiler size is spot on in length and diameter, and sits at perfect height. The injector gear (think that's what it's called! as seen in the top photo) needs to be swapped to the other side and a horizontal tank added to the fore of it.

Funnel and domes are a bit skinny but right height, and to be 100%, each needs to be moved rearwards by varying degrees. The bell can be removed and a new dome and whistle added in front of the cab.

The headlamp needs changing to the big box style (and fitted with an LED) although later they were made smaller?

A bit of a spoiler is the tender, whose chassis is overall 10mm too long, the body itself is 12mm or so too long and 3mm too high while the tender bogie axle centres are 2mm, and bogie centres 6mm over size.

Not too much we can do about that as this loco is tender drive. It may be possible to lower the body a mm or two, and removal of half the tender rear internal weight and a shortening of the body is a probable option for me although this would sacrifice pulling power. But then it wouldn't be on large trains in my world.

More to come. . .