Carrus and Carroballista

[D B Campbell]

The other image, from Trajan's this time, veiwed in context of the scene seems to show a 3/4 frontal view.

Aha -- now I see where you're coming from, Randi.
(And I must say I love your Photoshop'd TC images.)

Yes, you're right -- it's too interesting not to investigate. Keep doing what you're doing!

[P. Clodius Secundus]

Absolutely interested. I'm sure a lot of other people would also be.

I'd pay for a set of dimensional plans, and I'll bet I'm not alone there. The details like how you hold the axle in place, but make it movable for different loads, for example would be worth the price of the plans all by itself. (well, don't go crazy with the price... :lol: )

Not being a natural born carter, I'd have to think a long time to come up with the ideas you've already had, make mistakes you've already corrected, etc. Does the iron axle fit fairly snugly in the copper tube, and do you pump it with grease? (I admit, I've considered the front axle bearing from an old bicycle, concealed in a wood block. Don't kill me.)

If there's sufficient interest in the subject perhaps I should initiate a how-to thread or find an appropriate venue to publish the research. What I've got is mostly a collection of images of different iconographic and archaeological items that I used to arrive at my design. If I can write up proper attributions I'll gladly share that with anyone. I'll have to look back through my notes to see what evidence there is for smaller carts. I was aiming for the standard two-mule carrus but the single-mule cart is still a common sight around the Mediterranean today. I've got a cache of Visio drawings that I did to try out ideas let me see what I can come up with. Most of the cart was built freehand on the shop floor but I could make them into dimensional plans. No copyright worries on my own drawings. As for payment, I don't know if I'm ready to lose my amateur status. Maybe I could make e-copies available for a small donation to RAT. .... Don't be sheepish about the bicycle hub idea. I thought about that as well, but in the end it wasn't necessary. We dragged mine all around the field in Maryland with just a dab of grease on the iron axle. I've thought about making an all-wooden axle, but this works fine for now.

[P. Clodius Secundus]

I'm working up a set of detailed plans along with a B.O.M.(Bill Of Materials) and some helpful assembly hints. Hopefully I'll have some spare time to work on it through the Holidays. I'll try to come up with plans for a smaller cart as well. If anyone has historical references or images of single-mule carts that would be helpful. I found my file of photos from the wheel making process. Here's how....

1. Cut out a disk of heavy plywood the desired size of the hubs. I used 3/4 inch exterior grade about 8 inches in diameter.

2. Choose the number, shape, and size of spokes you want. From my research 8 spokes seems to have been the norm. There is evidence for both fancy spindle turned or just simple tapered shapes. I used pressure-treated porch railing spindles from Home Depot. They are cheap, sturdy, and they come already turned to a cool shape. If you have access to a lathe you could turn down your own instead. If you do, make sure to leave the last 4 inches on either end square or rectangular in cross-section so they can be glued to the hub and rim. The overall length of the spoke will be the radius of your finished wheel.

3. Sharpen the hub ends of the spokes by cutting off each side of the tip at a 22.5 degree angle (for 8-spoke wheels) Each spoke will then from a 45 degree pie-slice of the hub. (see attached photo)

4. Glue and clamp the spokes to the plywood. GorillaGlue works well. Make sure that the spokes are aligned and that the distance between the ends is roughly equal.

5. Glue another disk of plywood to the other side and keep adding various size disks to match the profile of the hubs you want. Note, Roman hubs and military ones especially, appear to have been more chunky and less tapered than modern wagon wheels. Similar to the way artillery carriage hubs compare to buggy wheels. Bore out the center of the finished hub to match axle size. If you can find copper pipe that will fit snugly over the axle it can be used as a bushing/sleeve. I used 3/4" ID copper over 3/4" steel rod.

6. Cut out a ring of thinner plywood to match the outer diameter of the wheel with an inner diameter that is about 4 inches smaller. This thicker rim is another common theme on Roman wheels. Glue it to the ends of the spokes.

7. Fill in the gaps between the spokes around the rim by gluing in arcs of wood the same thickness as the spokes. Small wedges can be used to fill in around the hub.

8. Glue another ring on the other side of the rim. This one can be made in sections to mimic the individual rim sections (called felloes) that make up a real rim. Just be sure to place the seams between the spokes not near them since this will weaken the wheel.

9. Your local metal shop can cut and roll a set of wheel hoops to the proper diameter. Mine cost @ $50 USD for the pair. I was going to weld and heat shrink them over the wheels but it wasn't necessary. I ended up countersinking some nails straight through the bands and the welding them in and grinding the heads flush.

10. Add some putty and paint and a dab of grease in each hub and you've got a set of "spinners" for your "fly-Roman-hoopdie".

[Gaius Julius Caesar]

Danged, that looks pretty professional Randi! 8)

[P. Clodius Secundus]

Here's a new collage of Visio drawings I've made up of some of the ferro-ballistae designs out there. The top two are Taurus Magnus and Carnifex. The one at lower left is my design. the middle one is from Trajan's. Lower right is off a photo from Vechten I think. I've taken the liberty of adding covers to the field frames on that one. If anyone has other good pics of iron-framers please post them and I'll add them to the database.

[P. Clodius Secundus]

I had promised to post some plans on building a full-sized mule cart, the Roman Army's equivalent of the Deuce -and-a- Half. Here's the first installment. Please keep in mind the follwing:
1. All measurements are in US units and based on standard dimensional lumber. I'm not familliar with the metric/EU equivalents, sorry :? .
2. These plans are being reverse engineered from my existing carrus which was built using a mix of standard size lumber and reclaimed wood from a local demolition site. I have taken that into account and included modifications I plan to make or would include in my next build.
3. I have resorted to using some modern methods and fasteners. I have done my best to keep the appearance of period correct joinery techinques (pegs/trunnels and as few expensive iron nails as possible). If you feel compelled to build one using only period methods please keep us informed of your efforts.
4. I have tried to establish reasonable dimensions based upon the available iconograpy, wheel ruts, and similar finds. To my knowledge the only known finds have been of civillian carts.

[AuxArcher]

Randi, you are doing a great job with the plans. I just peeked at them, and I have the sudden urge to build one too Alas, other projects are first in line.

Speaking of mules, I'm going to visit a canal museum in Pennylvania over this weekend, and during the summer, they give rides on a restored canal boat drawn by a two mule team. If I can, I'll talk to them - maybe they can give us leads to mules in our province.