Waveydavey

The diagram of an OAA in the Don Rolland book ‘British Railways Wagons’ gives a total height of 2235mm which scales to 29.33mm in 4mm scale.

Once you correct the overall height you’ll find that Hornby put the buffers in the wrong place and you need to replace them about 1.5mm higher.

Ah, those TOPS location codes bring back some happy memories,

Interesting to see one wagon from each pool is recorded as being loaded with bloom which you can’t load on to coil cradle fitted wagons. Wonder if the numbers had gotten mixed up and it was BBAs that had been loaded instead.

 One thing you don't need to do is alter the springs as the Bachmann TTA is basically a TTV to look at as they have leaf springs. The TTAs have Bruninghaus springs. So if you want an accurate TTA you need to change the springs.

I’m not sure it’s entirely true that air brake conversion happened at the same time as the fitting of Bruninghaus springs George.

Here’s one of mine Martyn,

I removed the air distributor and tank and fitted two vacuum cylinders. You could add some linkages if you felt like it but I’m not sure how they are laid out. This one is still a work in progress and will get safety loops before it gets out on the layout.

Nice to see both ducket widths and two ballast box variants too.

 

And the two types of brake gear on the drawings. Single shoe for the early ones and and double shoe for the later builds.

I just hope they now understand that UK models need to have 26mm long axles and W irons the proper distance apart. Getting P4 wheels into the HAA and Shark is somewhat challenging.

Looking at Paul Bartlett’s photo site it seems that the UM liveried tanks were withdrawn in 1981ish and were replaced by similar blue liveried vacuum braked tanks. These were then replaced in 1984 by air braked ex caustic soda tanks.

I had high hopes for a fleet of these Heljan tanks for my 1975 Alloa based layout and they are a pretty model. Unfortunately there are so many annoying faults that I have abandoned any thoughts of using them. I could just about cope with reworking the trenches that represent the weld lines on the tank, replacing the hugely overscale axleboxes and the clart on with making space for P4 wheels but resolving the excessive ride height finished off any enthusiasm and I decided to wait for the Oxford version or the long promised etched chassis for the Airfix/Dapol kit.

I’m in Middlesbrough.

Modelling Central Scotland in 1975 in P4 for my own layout and occasionally 1980s North East England in EM for Rountrees Sidings.

Here’s a couple of photos of one of my tanks to show how they are coming along.

The other tank I’m working on seems to have quite a bit of twist in the chassis. Has anybody worked out how to get these tanks apart so I can see if I can straighten it? Can’t see any screws so I’m assuming the upper part of the tank is glued fairly strongly to the bottom of the tank/chassis moulding.

I have recently bought a couple of these Lima HO tanks with a view to seeing if I could make them into a vaguely convincing representation of a couple of ferry tanks to run on Clackmannan Goods. Not going to win me any points at P4 gatherings but they’ll give a bit of variety to the freight comings and goings on the layout.

First assessment was that the buffers were too close together and the bogies were both too close together and rubbish. The chassis measured up as an acceptable width for 4mm scale so I set about hacking. One tank came with a top loading hatch, platform and access ladders while the other didn’t so I removed them. I also removed the underframe trusses as they looked a bit unrealistic.

It’s a huge simplification to say that ferry tanks come on two main types of bogie. German ones come on a type of bogie commonly seen on VTG steel wagons and Cargowagon vans and flats. French wagons tend to run on French made Y25 bogies which are also fairly common on UK domestic stock. I had two pairs of Bachmann Y25s from their BDA wagons going spare so I’ve used them. New bogie centres were estimated and mounts made and glued into position. Getting P4 wheels in involved much filing of the bogie frame and trimming of the brake shoes to create enough clearance.

Work is now centred around making the underframe look realistic. LMS RIV buffers have been fitted along with brake and discharge equipment from S Kits and ferry lashing rings from 51L and label clips from Colin Craig.

Still to do are new end platform handrails and steps, RIV screw couplings and solebar level handbrake wheels.

I don’t think the Colin Craig OAA underframe bits were ever available openly Mike. I think they were just test etches that Colin had done. I got a pair that were etched in very thin brass and they fell to pieces as I tried to assemble them. My suggestion to Colin that they needed to be etched in a slightly more robust thickness of brass with a bit of strategic beefing up of some of the tiny bits didn’t seem to have a successful reception.

To get the height of my OAAs to match the drawing I have (29.33mm) I found it necessary to pack the Cambrian solebars down by 80 thou which then caused the bodies to warp. Even with this packing and the buffers in the correct place they are still a bit low so may need further remedial work. As a result my two sit in a semi abandoned state awaiting further inspiration.

You going to build one in blue/grey Phil?

On passenger lines the magnet is usually about 200m before the signal it is associated with.

On goods lines the magnet can be placed at the signal.

I have recently been considering such a conversion, to mix in amongst some Accurascale Cemflos, as I’ve been given a Hornby Collectors Club PCA.

The early batches were 15’ wheelbase so a Bachmann TTA chassis could be an option with some modifications.

Can’t see me doing anything on this in the immediate future so I’ll be looking forward to picking up some inspiration if you get cracking on it.

Fran,

I model 1975 which is right on the changeover from preTOPS to TOPS. In your research have you been able to identify when the change was made to most of the fleet so I can buy the right versions or mix of versions?

Cheers

Any idea of the cost of the ‘bag of bits’ and what’s in it?

I could do with a few sets of the pre-refurbishment exhausts for my 101 fleet.

You can buy spare Heljan fuel tanks from Howes for not much money if you don’t want to scratchbuild them. They’re a bit wide but on a Lima 27 that will be a minor issue.

From a study of all the photos I could find I worked out the extra grills were fitted in 1977. A few years after the fitting of the ETH generators.

Subsequently I’ve seen photos of the odd loco with one or two grills before that date but not the full set.

The 27/2 grills are available from Shawplan.

Sounds like a good idea for a layout Stuart. Ben Alder’s photos have been very inspiring for me too.

I’ve been pondering whether one of those early PCAs would be a good option for mixing in with Accurascale Cemflo. If you start building one I might pull my finger out and have a go myself.

I was going to say use whatever is appropriate to the location and era you are modelling but I see it’s for a fiddle yard.

In that case it doesn’t really matter what rail you use as long as you gauge it correctly so use rail that you can get hold of for the lowest cost.

If you’re using copper clad sleepers and they are double sided it’s good practice to make sure you gap the underside before laying to avoid the chance of any annoying shorts.

Rumney models are doing a good selection of springs and axleboxes these days. The quality is excellent.

Yes Martyn, I just spaced the plastic frame down with plasticard till the buffer height was about right. On the long one I used the Replica frame and added a variety of Heljan and Lima DMU bits. The short one was easier still as I just fettled a Lima 101 underframe to fit.

I’ve used two Replica chassis, one long and one short, and both have needed the frame spacing down to get the buffer height right.

Loving the 303 build. Quite fancy a pair for a future Glasgow suburban layout I’ve got in mind.

Hurray. A blue one with the two digit headcode box.

I used some around ten years ago on some VEAs for Roundtrees Sidings.

I’d guess they were Modelmaster decals.

ISTR back in the 70s and 1980s the Airfix Africa Korps were the preferred option for model BR personnel.