IZA (Hfirrs3) Cargowaggon Twin Vans in S7

[Pugsley]

Sometimes I just need a deadline to spur me on to achieving something - otherwise too much thought occurs, and not enough action. I wasn't going to enter, but then Dave Long inspired me with his IVA van in P4 and it reminded me that I'd been thinking about the Cargowaggon twin vans for a while, so I took a decision to get on with it.

 

Photo copyright Martyn Read, used with permission.

 

It's going to prove an interesting project, as none of the castings I need, axleboxes, buffers, etc, are available commercially so I'll need to design these and get them made, either by myself or contract someone to do it. Certain parts I've developed for the Nitric Acid Tanks will be useful for this, such as the axleguards and axleboxes, which will only need slight modfication. Conversely some of the parts for these will prove to be useful for the Nitric tanks.

 

I'll devise and produce etched components for the chassis and body, to show how straightforward it is and how anyone with access to a computer and a vector drawing package (you don't even need to use a CAD program) can produce their own. I'll also be giving resin casting a go for the non-working details, so any castings with the exception of the buffers and axleboxes. I might try to incorporate working leaf springs, but that might be a challenge too far, given that I have to draw up all the bits, get them made and assemble the model!

 

I owe a big thank you to Martyn Read (GloriousNSE) - not only has he allowed me to use one of his pictures to illustrate the thread, he's also provided me with some detail pics taken from different angles to mine, that are going to be a big help with this project.

 

More to follow soon.

 

Edit - I know this probably won't be considered scratchbuilding by the purists, but I think it's a modern take on it, just taking advantage of the modern tools at our disposal.

[dave_long]

Are you going for a clean or down right filthy version as in the photo?

 

I'll be interested in seeing what you design ( and how ) for this project. Atleast in 4mm I've got buffers... but thats about it!

 

I see the twins have the solid underframe beams, the singles have both the solid beams and the open frames, I'm tempted to try both.

IIRC there's a good number of IZA images on flickr.

 

Dave

 

Edit: I'd forgotten that Jim SW has drawn a IZA wagon and its on his website http://jsmithwright.demonweb.co.uk/other/drawings/drawings.html

[Pugsley]

Thanks Dave - I'd forgotten that Jim had done that as well, that's going to be very useful! The attraction of the twins is the relatively simple fishbelly frames, and general lack of detail, so it should be quite a straightforward project, I hope! I'll have a good look at Flickr as well and see what I can find.

 

I'm not sure quite what condition they'll be in yet, probably quite dirty but not as filthy as the ones in the picture above - I'll have to trawl around and see if I can find any photos taken in the late 80's/early 90's.

[Fat Controller]

You might find buffers available from Appleby- I believe John Talbot did some O-gauge models of German prototypes in 0.

[dave_long]

You might find buffers available from Appleby- I believe John Talbot did some O-gauge models of German prototypes in 0.

He definitely did them in 4mm (according to the price lists I have ) so he may well have done them 0.

[Pugsley]

Thanks for the suggestion, but the Appleby Parts are virtually impossible to obtain it seems to me. I'll do my own, I think - part of the fun is in the challenge

[Talltim]

I thought I had a few pics of these but it turns out to be a different twin variant

CargoWaggon pair by ta||tim, on Flickr

CargoWaggon pair RIV details by ta||tim, on Flickr

CargoWaggon pair end by ta||tim, on Flickr

[Pugsley]

Thanks Tim. Those are photos of the second batch of twins, now known as Hfirrs4, which are almost the same as the earlier ones but slightly wider and taller. It's interesting as it looks like they've been recoded at some point since those photos were taken, so I may have to code mine as Habbfins instead. More research required!

[hmrspaul]

Thanks Tim. Those are photos of the second batch of twins, now known as Hfirrs4, which are almost the same as the earlier ones but slightly wider and taller. It's interesting as it looks like they've been recoded at some point since those photos were taken, so I may have to code mine as Habbfins instead. More research required!

 

No, sorry, looks like the third batch, built 1991, Design code E753.

 

Paul Bartlett

[hmrspaul]

_{I have added a collection of photographs of these "twins", illustrating the three diagrams and four batches of them. All from their early days - even so they appear to be capable of accumulating dirt as well as SRly NPCSS during the steam railway era!}

 

_{See http://paulbartlett....lio.com/twinvan}

 

_{A noticeable difference is the holes in the end stanchions of design code E668.}

 

_{Paul Bartlett}

[Pugsley]

No, sorry, looks like the third batch, built 1991, Design code E753.

Thanks for the clarification Paul, I wasn't aware of the different design code between the 1989 (IPE710) and 1991 (IPE753) built vehicles, and was counting the much later vehicles, with the rounder roof profile, as the third variant. Do you know what the differences between the two design codes are, please? Also, am I correct in thinking it was the first batch of IPE668 that had the holes in the end stanchions?

 

Thanks for taking the time to post your photos as well - I'll have a good look at those later.

[hmrspaul]

Thanks for the clarification Paul, I wasn't aware of the different design code between the 1989 (IPE710) and 1991 (IPE753) built vehicles, and was counting the much later vehicles, with the rounder roof profile, as the third variant. Do you know what the differences between the two design codes are, please? Also, am I correct in thinking it was the first batch of IPE668 that had the holes in the end stanchions?

 

Thanks for taking the time to post your photos as well - I'll have a good look at those later.

 

Yes, 668 were the 1986-7 batch with holes in the end stanchions, and confusingly got renumbered..

 

Sorry, I don't have diagrams of any of these.

 

Paul Bartlett

[Pugsley]

After some measuring from photographs, and some deft Googling turned up a drawing of the very axleboxes fitted to these wagons, the first component has been created, virtually at least:

 

 

It needs a little refining, some edges need filleting, and there are DB and FAG logos to add, but it's 95% there. There's 2-3 hours work gone in so far - I'm recording the amount of time spent on each stage as I'm curious to see just how much time goes into a model - I don't normally count it (which is probably just as well sometimes )

 

More deft Googling has also turned up a drawing of the buffers fitted to these wagons, so after the axlebox has had the final tweaks, those will be the next parts to be drawn up.

[Pugsley]

Following another 30 minutes of tinkering, I'm happy that this particular part is complete for now. I'll draw up all of the parts required, before sending them for printing, it's going to be much more economical that way.

 

 

The text is a little too big, but it will only be 0.2mm high when scaled down (I tend to draw components for casting at full size, then scale them down later, as required). If it still looks too big, I can gently rub it down on the master, once created.

 

On with the buffers!

[dave_long]

That looks really good.

I presume you get a master printed then cast them at home? If so what do you use, I'm hoping to build a master from the VIX parts and scratched springs then cast them. Shortliner recommended Davids fastglas resin (halfords).

 

Looking forward to the buffers.

 

Dave

[Pugsley]

Thanks Dave. Yes, I'll use the print as a master, but I expect I'll get the buffers and axleboxes lost wax cast in brass - these will be components that work in the same way as the real thing, so I don't think that resin will be suitable. All other components will be cast in resin at home though - I've got some of this stuff to try:

http://www.mbfg.co.u...stics/1773.html

 

Which will be perfect for the other detail parts. I think that the Fastglas resin you mention is a styrene resin, rather than the polyurethane that I'll be using - I don't know what advantages, or disadvantages this has, other than perhaps the smell! Styrene resins can be a bit niffy.

[Pugsley]

With a further estimated 3 hours of work, the buffers are now complete:

 

 

The idea is that they're fully sprung and self contained, so they can be put in the correct position on the van without having to compromise anything to accommodate parts projecting from the back of the housing once compressed.

 

 

The hexagonal cut-out is designed so a 10BA nut will sit in the housing, to retain the head assembly. In the picture above, the red part is the shaft attached to the head, this will be threaded 10BA and the whole head assembly will screw into the nut in the housing, retaining the head. When fully compressed, the retaining nut will be just shy of the end of the housing. Due to the method of assembly employed, the buffers will, most likely, need to be cast in 3 pieces, with the outer housing (orange) soldered on to the head before final assembly, as I don't know how well they will cast in two pieces. This is something I can pick up with the casters nearer the time - I don't know who will be doing it yet though!

 

The studs on the back will fit into locating holes on the bufferbeams, to provide a positive location during assembly, I may yet make them hexagonal to look a bit like the bolt heads that secure the actual buffers, but they're probably OK as they are.

 

Finally, a rendered version in almost Cargowaggon blue:

 

 

The internal buffers will be next, then the tricky part starts - working on the etches for the chassis.

[Pugsley]

As you might have guessed, I've had a day off work today so have been able to concentrate on this project pretty much all day. Another two hours work, including some additional research, has seen the inner buffers for the wagon completed, with only about 45 minutes of that being drawing time. I've modified the head and housing from the outer buffers to create these, which sped up the process immensely. These will also work in the same way as the outer buffers, being self contained.

 

 

Next job is to start on the chassis of the wagon - expect updates to become a lot less frequent from now on

[tomstaf]

The idea is that they're fully sprung and self contained, so they can be put in the correct position on the van without having to compromise anything to accommodate parts projecting from the back of the housing once compressed.

 

The hexagonal cut-out is designed so a 10BA nut will sit in the housing, to retain the head assembly. In the picture above, the red part is the shaft attached to the head, this will be threaded 10BA and the whole head assembly will screw into the nut in the housing, retaining the head. When fully compressed, the retaining nut will be just shy of the end of the housing. Due to the method of assembly employed, the buffers will, most likely, need to be cast in 3 pieces, with the outer housing (orange) soldered on to the head before final assembly, as I don't know how well they will cast in two pieces. This is something I can pick up with the casters nearer the time - I don't know who will be doing it yet though!

 

 

Hi Martin,

 

This is looking very promising. It's nice to see you thinking about construction and practicalities too. Something often overlooked, or given little attention based on some of the kits I've assembled.

 

How many are you going to have - a nice rake behind a nice RfD Blue roof 47 ( ) would look tasty Or incase you feel like painting your tractor in RR then:

 

Cheers

 

Tom

[dave_long]

Certainly puts the white metal 4mm versions in the shade. I must get round to doing some 3d work I've not done anything since using gmax with the old flight sim.

I suppose its more crucial in S7 as it's larger so the detail is needed as printing that text in 4mm probably wouldn't show up.

 

I don't suppose that great Google work showed up anything with regards to the continental screwlink couplings? The only thing I could find was on the old rmweb which is still offline.

 

Dave

[Pugsley]

Hi Martin, This is looking very promising. It's nice to see you thinking about construction and practicalities too. Something often overlooked, or given little attention based on some of the kits I've assembled.

Thanks Tom, although I'd be daft not to consider the practicalities of construction, given that I'm going to be building it as well! I've planned to build 2 or 3 sets, should look good behind the 37, and no repainting required

[Pugsley]

Certainly puts the white metal 4mm versions in the shade. I must get round to doing some 3d work I've not done anything since using gmax with the old flight sim. I suppose its more crucial in S7 as it's larger so the detail is needed as printing that text in 4mm probably wouldn't show up. I don't suppose that great Google work showed up anything with regards to the continental screwlink couplings? The only thing I could find was on the old rmweb which is still offline. Dave

Thanks Dave. I don't know if this much detail is really necessary, even in 7mm scale, but I thought I'd include it while creating the model for the masters - if it doesn't come out in the printing or casting processes, I won't be too upset. Like anything, I like to try and push the boundaries of whatever I'm trying, so I will be happy if it does work. Like you say, I don't think you'd need this level of detail in 4mm scale, although I can scale these models down to that size, I think it would be too small for the printing process.

 

I haven't looked into couplings much yet, I'll let you know if I find anything.

[Pugsley]

[rolf harris] Can you tell what it is yet? [/rolf harris]

 

 

This is just the basic shape of the end of the vans - there's loads to do yet in terms of cutting slots for the various parts to fit on, including buffers and drawgear, and also the slots that will allow the ends to fit on the floor. The construction consists of a flat floor plate, which the ends and chassis rails will fit into with tabs and slots. There's probably another 2 hours gone into this part, plus another 20 minutes for the floor, so in total I'm now up to nearly 10 hours on this project so far, which does include some, but not all, of the research required.

[Pugsley]

I don't suppose that great Google work showed up anything with regards to the continental screwlink couplings? The only thing I could find was on the old rmweb which is still offline.

There's some useful stuff in here:

http://www.rgsonline.co.uk/Railway_Group_Standards/Rolling%20Stock/Guidance%20Notes/GMGN2690%20Iss%201.pdf

about vehicles fitted with UIC drawgear (and UK equipment). I'm sure there's more out there, but I haven't uncovered it yet. HTH

[Pugsley]

Here's how things look after another 3 hours this afternoon - the basic shapes are coming together quite quickly, but I'm expecting progress to slow considerably when it comes to the fiddly bits however.

 

 

The frame the other side should be the same as this side, reversed, as long as the support stanchions and the like are in the same places on both sides. Looking at the photos I have, so far they seem to be symmetrical, which is good news! I'm assembling the basic parts as I go along, as the assembly itself will be useful for creating some of the trickier parts, such as the end supports, in situ, making reference to what's already there.

 

The good news is it's starting to look like it's supposed to, which is always a bonus!