NZR Da from a Frateschi G-12

The NZR Da class locomotive was to me the sight, smell, and sound of railways when I was growing up in the sixties. Much like older peoples grew up with the sight, smell, and sound of those hissy things.

The Da was everywhere - on local goods shunts, on the Scenic Daylight and overnight expresses between Wellington and Auckland, and on subbies. Even the most beautiful Silver Star express in its early days. They were just everywhere.

What needs doing then?
The Frateschi "Da" is another of their New Zealand look-alikes that's reasonably close, and with a bit of work you can make it look even better, and capture that proper look of our own NZR Da class.

Over the years, Frateschi have released three NZR versions that I know of -

Bo-Bo (four-axle) in Fruit Salad

A1A-A1A (six-axle) in Fruit Salad

A1A-A1A (six-axle) in classic red.

Ok, I haven't started this project yet - other than purchasing a couple of extra bodies that are sold separately - so much of the following can be argued and will update as I gain more info and feedback from fellow modellers.

But the following is based on my many years of real life observation (ah, the sounds and smells!), research, and also many drawings and a multitude of photographs. And staring endlessly at the model from all angles.

In the end, I don't want to be a rivet counter, but have found that with models, getting most if not all of the measurements at least correct or close, greatly helps in getting the correct overall look. And that's my ultimate goal.

In searching for accurate drawings of our NZGR Da, none appeared accurate in all areas, and especially in the all-important area of the Da's characteristic 'waist' behind the cab. That is where the long hood has a two-panel tapering section immediately aft of the cab to match the narrower shorthood.

Luckily I found an NZRLS drawing of the the lighter version Db class. This does show the correct 'waist'.

Just watch it though - the Db body is a smidgen lower and narrower than the Da, to fit smaller loading gauges on branch lines.

So, looking at drawings of a Da and Db, and based on body length and a few other base measurements, I estimate this model to be approximately averaging(!) 1/77th scale - pretty close to OO scale's 1/76th then.

It's probably best to decide on one particular Da you want to represent, hunt down as many photos as you can of it, and then apply those changes to the Frateschi, because over the years, like any other modelling subject like this, there were many differences even within the same sub types. With the Da, bogie types and roof detail are a good example of this.

Chassis
The bogies are Phase 3 style, but brakes are single pads on the drivers rather than double.

The bogie outside axle centres measures 3.5mm too short.

The bogie pivot centres measure 4mm too short.

The driving wheels are ~1mm too small, not noticeable, while the idlers are pretty much spot on.

The fueltank and batterybox between the bogies need enlarging vertically (dropping) by ~2mm

Oh, and the footplate is exactly spot on height from rail level!

Not tooooo bad over all

Body
The body is a mixture of Phase I (the headlights being unshrouded), and Phase III in some of the roof detail.

Overall the body measures ~2mm too high from the footplate, and is ~2mm too short. Doesn't sound much but it does contribute to the overall too-short, too-tall look of this Frateschi.

The footplate skirt is perfect height.

The most obvious inaccuracy, and the one that annoys me the most, is in the long and short hoods being the same width. The longhood should be fatter with a tapering section aft of the cab, and the short hood should be slimmer.

Body length
The ~2mm shortness mentioned, is in the cab section where the main side window is a smidgen narrow, but the smaller windows are each 1mm too narrow.

Body height
As mentioned, the body is overall ~2mm too high from footplate. Longhood needs 2mm removed above the side vents, while the shorthood needs 1mm removed from the bottom, and 1mm removed from halfway up.
SEPARATELY the cab parts needs ~2mm taken off the top and the curve reinstated.

Body width
The long hood and short hood are the same width - totally wrong for our version G-12! There needs to be a slight waist immediately behind the cab, where the wider long hood pinches in to be same width as the narrower short hood.

To acheive the correct hood plan shapes, the short hood back to the aft edge of the cab needs narrowing by about 3mm, and the long hood widening 1mm or so, aft of the two vent panels aft of the rear cab edge.

To summerise, both longhood and shorthood are 23mm wide.
The shorthood should be 21mm (63" life size)
The longhood should be 24mm (72" life size)

Shorthood needs narrowing by 2mm = 1mm each side
Longhood needs fattening by 1mm

Once done, the longhood needs a bevel so the top edge lines up with the top edge of the short hood - see waist photos for reference.

Cab front and rear panels (doors and their windows) need fettling to fit the resulting narrower shorthood and narrow section of the long hood.

Asthetics
The top dynamic brake fan diameter is spot on.

A nicer headstock wouldn't go amiss along with correct cow catcher.

The moulded-on hand grabs can be removed and replaced with wire.

Likewise the supplied plastic handrails are too thick and should be replaced with wire.

In summary

Refer to as many photos as you can find and use them as a guide.

References

• If you are were a member of the Yahoo nz-railchat group, there were photos of others bashing this model into shape under photo albums "12mm" and "Rays HOn31/2 models". Maybe somewhere else now?
• Ken Devlin's photos via the KiwiBonds site
• Kiwi xyz photostream on Flickr
• Jokertrekker photostream, N.Z. Railways, North Island collection on Flickr
• Just do a search of Flickr
• Measurements from the Da drawing in "NZR Locomotives and Railcars 1980" by T. A. McGavin (page 15)

More to follow once reconstruction begins.