1:25 Eritrean 0-4-0T Locomotive "202 series"

[Plastic_Goth]

My parents recently visited Brooklyn, N.Y. where I live and we got lunch at an Ethiopian restaurant and coffee house in the neighborhood of Bushwick. There they had a book on their shelf (African Train - Hugues Fontaine) which was in the French and mostly illegible to me. However, it renewed my interest in European-built rail hardware on the African continent. 

As well, after purchasing some 1990s vintage Model Team sets on the aftermarket, I have an interest in larger-than-minifig scale models. The garden gauge LEGO models of user Tenderlok are a real inspiration as well. I decided to pursue a project that would use official LEGO track as narrow gauge and scale the rolling stock accordingly. I decided on a prototype built by Italian manufacturing company Breda for export to and use by Eritrea. 

Engines dating to the 1920s are still operational on the Eritrean rail link between the capital of Asmara and the port city of Massawa. It is well for my reference that high definition videos of the locomotives in action exist! 
 

http://railpictures.net/photo/525923/

 

My model, in virtual:

 

I hope soon to build this model in real bricks. I should add more detail that is not possible in bricklink's Studio, such as pipes around the boiler with flexible rods. I would also like to accommodate a battery with two motors working in tandem somewhere in the cab. 

The valve gear is exaggerated somewhat for kinetic aesthetics. I am open to ideas for improving the detail of the piston faces. They are plain to allow the axles to move in and out of the technic bricks, but I feel some of the character of the locomotive is lost there. 

Edit: I originally titled this as a 1:20 model but Sven has informed me that the actual scale, referencing the LEGO track gauge of 37.5 mm, is 1:25

 

Thank you for your attention,

Erik Frobom

Edited September 21, 2018 by Plastic_Goth

[Capparezza]

Wonderful rendition. It's funny, I watched a documentary in German television about the Eritrean Railway just a couple days ago (you can watch it on YouTube here). Thanks a lot for linking that great video, too!

[Sven J]

Hi Erik,

I'm happy to have inspired you, so I'll take the liberty to add my two cents to your model:

This is a wonderful, cute little steamer! Much attention to detail, and very well-proportioned overall design.
And the renders are absolutely awesome. Can't wait to see this beauty in real bricks!

However, regarding the track scale, I think you are mistaken. Track width is measured between the inner edges of the rails, so LEGO track has ~37.5 mm gauge. For a prototype gauge of 950 mm, this would mean roughly 1:25 scale. But never mind - for garden railway models, it's quite usual to have the track built to a different scale than the rest of the model... Main thing is to make the proportions look right, and as I said, you surely managed to do that.
(Edit: The wheel diameter also indicates that the whole model is held in a scale of around 1:25 rather than 1:20 - 30.4 mm for LEGO's steam locomotive drivers, 720 mm for the prototype according to this source.)

As for the cylinders: Have you considered making them 1 stud longer? That way, there might be enough space for the piston rod inside to move without temporarily protruding from the cylinder front, so you could do some detailing there.

(Btw: That is a very strange kind of cab door both on the real thing and the model... never seen something like that before...)

Best regards,
Sven

Edited September 21, 2018 by Tenderlok

[LEGO Train 12 Volts]

Very nice little (with large scale ratio) locomotive!

At first glance I thought I saw one of Sven's masterpieces ...I hope to see the model in real bricks! 

 

[Plastic_Goth]

6 hours ago, Tenderlok said:

Hi Erik,

I'm happy to have inspired you, so I'll take the liberty to add my two cents to your model:

This is a wonderful, cute little steamer! Much attention to detail, and very well-proportioned overall design.
And the renders are absolutely awesome. Can't wait to see this beauty in real bricks!

However, regarding the track scale, I think you are mistaken. Track width is measured between the inner edges of the rails, so LEGO track has ~37.5 mm gauge. For a prototype gauge of 950 mm, this would mean roughly 1:25 scale. But never mind - for garden railway models, it's quite usual to have the track built to a different scale than the rest of the model... Main thing is to make the proportions look right, and as I said, you surely managed to do that.
(Edit: The wheel diameter also indicates that the whole model is held in a scale of around 1:25 rather than 1:20 - 30.4 mm for LEGO's steam locomotive drivers, 720 mm for the prototype according to this source.)

As for the cylinders: Have you considered making them 1 stud longer? That way, there might be enough space for the piston rod inside to move without temporarily protruding from the cylinder front, so you could do some detailing there.

(Btw: That is a very strange kind of cab door both on the real thing and the model... never seen something like that before...)

Best regards,
Sven

Sven, it is validating to hear your praise for my model. As well, thank you for your correction regarding the scale. A part of my mind knew that truth about track gauging, but I had forgotten it as I leaped into this model. Rather than numbers I use my eyeballs primarily, so I am happy to hear that the overall proportions are well received. I looked for such a reference that would give me the diameter of the real locomotive's wheels, but failed, so I am also thankful that you were able to find one for me. If I go ahead and design the Mallet types that operate on the main line of this railway, it will benefit the accuracy of the model to know their driver diameter. 

My main issue of building out the pistons and steam chests one brick is that they are no longer in line with the steam pipes, thus detracting from the proportionality I've been able to keep throughout. It's a trade off but it might be worth it. I have revised the model and I think I like them with the longer pistons. I've used brackets to put round plates on their fronts . 

 Erik

[zephyr1934]

That is a very nice build! Only suggestion I can see is that the footboards on the pilot are likely solid planking rather than grating, if so, then panels would make sense over the fences.

 

On 9/21/2018 at 4:14 PM, Plastic_Goth said:

...If I go ahead and design the Mallet types that operate on the main line of this railway, it will benefit the accuracy of the model to know their driver diameter. 

My main issue of building out the pistons and steam chests one brick is that they are no longer in line with the steam pipes, thus detracting from the proportionality I've been able to keep throughout. It's a trade off but it might be worth it. I have revised the model and I think I like them with the longer pistons. I've used brackets to put round plates on their fronts .

Okay, two more suggestions, build the rigid engine first before attempting an articulated, you will come to hate the tight radius of normal lego curves. Solutions can be found (easiest being https://www.bricktracks.com/ but there are brick built solutions that can handle R44 too). And for the steam chests, why not extend them one stud and then shrink the steam pipes by one stud to keep the centered relationship?

All of the above are minor, the locomotive is great.

[Paperinik77pk]

Hi Erik, 

It is a very nice locomotive!!!

Someone says that the first look is important - this MOC immediately gave me the idea of a small, economic Italian locomotive. And even if it is Eritrean, the feeling was correct. Both locomotives, the mallet and the small one, were made by Ansaldo and Breda - two big italian manufacturers.

And if a MOC immediately gives a so precise feeling...well it means it is a very good one! 

Only some suggestions when you'll build it for real (all things I've encountered experimenting large scale models  )

• I think one XL motor could be fine for moving this beauty - the batteries won't last so long, so using the BIG PF battery box with high capacity rechargeable batteries could be useful. 
• Try to keep the body as light as you can - e.g. my locomotives are built with 2-wide bricks to be more solid - but they're too heavy and I loose half of the power only to move the body. I'm currently making both of them lighter,
• Two axles locomotives may have problems managing the standard Lego curve radius and the switches, resulting in slowdowns and stress on transmission gears. Maybe Big Ben Bricks wheels are easier on tracks, but standard Lego wheels have some problems in managing large interaxles.
• Some parts (e.g. buffers , coupling rods made by old parts, headlamps holders, ski sticks) are quite unusual, so trying to simplify them using common parts will save you some money.

Keep up the good work!!!  

Davide

 

 

 

 

 

[Plastic_Goth]

Hi everyone, 

 

I've put a PF2.0 battery box and receiver (or rather an assembly that's equivalent volume-wise) and two motors into the engine. I'm not sure how reversing polarity works on the new system, or if it's needed for running two synchronized motors??   

 

 

[Sven J]

With an odd number of gear wheels between the two motors, both have to run in the same direction; so with one gear wheel coupling them, there's no need of reversing polarity.

Are you sure that the locomotive frame remains strong enough? Seems as if you had to take out quite a few bricks to accomodate the gear wheels.

[Plastic_Goth]

22 minutes ago, Tenderlok said:

With an odd number of gear wheels between the two motors, both have to run in the same direction; so with one gear wheel coupling them, there's no need of reversing polarity.

Are you sure that the locomotive frame remains strong enough? Seems as if you had to take out quite a few bricks to accomodate the gear wheels.

Understood, thanks. 

It remains to be seen how well the model will hold together in real life. I used a pair of 8 tooth gears set on the interiors of the rear drivers to off-phase the eccentric crank, otherwise, I'd have the motors transmit to the rear axle. I am curious what other solutions have been toyed with by others for creating the eccentric motion? 

[Sven J]

1 hour ago, Plastic_Goth said:

I am curious what other solutions have been toyed with by others for creating the eccentric motion? 

Very small bits of paper/double-sided self-adhesive tape put inside the wheel's pin hole, in order to prevent the Technic pin (with friction) from twisting.

Anyway, I'd recommend to use only 8-tooth gears or 12-tooth bevel gears to drive the axle (doesn't matter if it is the front or rear one): They need less than 2 studs width, so you can still build the frame around them. Frame and drivetrain are in fact the components which caused most of the troubles which I experienced with my models - they need to be very rigid and all gears secured against shifting, otherwise something will break under load.

P.S.: The new, larger cylinders really look better!