Madill 071 Mobile Tower Yarder

[JCON]

Very cool project!!!

[Beekster]

Jan 23, 2019 13:47:48 GMT -6 BUCKY said:

Excellent history and description! These brutes are pretty rugged!

Very rugged indeed, though not infinitely so.  With an all-up weight of about 43 tons, these machines are very hard on the old VVSS suspension units.  Collapsed springs aren't unusual.  Since they max out at five miles an hour, though, they hardly need suspension.  It's also pretty common to find a few road wheels totally devoid of rubber after all these years; that's harder on the track but again at such low speed and so few miles actually driven it takes years for bare wheels to wear out the inside surface of a track.

And an unskilled operator can cause havoc if a turn is too heavy or it gets hung up on an obstacle.  Bad things happen then:












Because of the weight and width of these things, they are always a Wide Load when being moved on the highway and that requires special permits.  Since the roads to logging sites can be rather steep and are usually bare dirt or rough gravel, a heavy prime mover is required to tow the lowboy trailer with the yarder on it. The trailer needs at least 50 tons capacity, and it isn't uncommon to find ex-military tractors pulling the load.  One Oregon outfit has used a Mack M123 and Oshkosh M911 for years; I will be building the Hobby Boss M911 and M747 in civilian garb to haul my Madill.

[BUCKY]

Yikes!!!

[Beekster]

Jan 23, 2019 14:19:44 GMT -6 BUCKY said:

Yikes!!!

Yeah.  Chainsaws aren't the only reason guys get killed in the woods so that we have studs & plywood to build our houses.

[RLFoster]

Wow, don't know how I missed this originally, but I'm solidly in now!!! Great project!

[JCON]

I've seen a few damaged ones up here from operator error... I have a few logging buddies who have taken me out before to their sites on the sides of mountains...

[BUCKY]

Sometimes, they don't hire the best qualified operators for jobs like that.

[JED]

Thanks for that Beekster,and Ax Men was the one I was thinking off,hard life !!

[Beekster]

Greetings once again, gents! I've been on something of a modeling hiatus for a few months, and beginning to get back to the bench again from time to time. This project has been dormant for many months, not least because it got a bunch of glossy orange paint slung on it last spring and that stuff takes ages to fully cure. Only thing to do is leave it be for a long time, and that's just what I did. The spar is now painted and the powered guyline sheaves attached. I've done some detail painting, and the whole thing has been sprayed with Dullcote to get a nice flat finish.




The bulk of the yarder is significantly more complete now. The roadwheels have the tires painted (base coat), the exhaust pipe has had some rust tones stippled on, and the radiator has been glued down and plumbed.










One of the problems to solve was the brush guard screens for the cab windows. I made up screens using styrene and etched brass mesh, but once painted I hated them. The mesh was much too fine; the operator wouldn't have been able to see a thing. So new guards are in progress. Here are the guards for the long windows, without standoffs but otherwise complete. Simple construction using strip and rod stock. The original item is shown for comparison. The two smaller guards are in process right now.


An earlier image showed the three powered guyline wires. Sad to say, I need to make new ones. I used a silver paint pen to give them a metallic sheen, but when they were completely dry the rigging thread became much too stiff. I hope I have enough thread to do three more. We shall see...

[dogfish7 (R.I.P.)]

Some fantastic Mini-Engineering, Beekster!

[JED]

Glad to see you back with more great work Beekster, I love this build

[Dukemaddog]

Man, I'm thrilled to see this back under production again! What a magnificent model!

[Beekster]

Mini-engineering indeed! This project has been on and off the bench for years as I've built stuff and rebuilt it when I wasn't satisfied. But it is finally looking something like the real thing, and that will get much closer once I can get the top deck on. Still a ways away for that, not least because I'll have to do some serious work making the engine bay and floor area good and grimy. Unless you've seen one of these up close, you have no idea how filthy everything gets. Like this:

This is a unit I photographed a few years ago in the midst of being scrapped. You are looking forward, through an empty engine bay, to the rear face of the rear winch bedplate.



This is inside the front superstructure, looking at the water-cooled clutches and brakes and the gears which spin the winch drums. The gears are regularly greased, and when the thing is operating that gets flung everywhere and winds up on the floor of the hull, along with leaking water, hydraulic fluid, dust, and copious amounts of wood chips. I have to make the rear area look something like this before I can carefully put the top deck on.

[JCON]

Nice to see the juices are flowing once again!!!

[Beekster]

If not flowing, at least a steady trickle. Seeing some results emanating from the long thought process will help things along; it usually does. Still, this particular project is continuing to force me to think up solutions that are quite outside my normal processes. It goes without saying that the rigging will have to be done after most of the assembly is done. You might think that securing the lines to the winch drums, spooling all the line onto them, then pulling through the various fittings on the spar is the way to do that. Not necessarily... Something that hasn't yet progressed to the photo stage are the small lines for the straw & tag drums--the two small ones forward & aft on a common shaft on the upper right side. Those lines need a utility termination on one end, and I've chosen to use resin copies of the cable ends included with the Tamiya Dragon Wagon. Great...but the end won't fit through the small sheaves on the spar that those lines run through. So at some point I will have to run the lines (several feet of them) through the sheaves, and set them aside. When the spar is on, I can pull the lines through the sheave mounts and fit the sheaves (they just push into place), then spool the rest of the line onto the drums. And as the various lines get threaded through their proper places and spooled onto the drums, I will have to keep them from tangling with each other. Working out that process has been one of those things that have been percolating in the back of my mind just about forever now. What prompted the solution now? I'm not really sure, but it must have something to do with seeing the major subassemblies get closer to completion and looking at mock-ups with a more critical eye.

[JED]

Always an interesting catch up Beekster

[Beekster]

Well, now...this will be fun...

These yarders typically have the most horribly worn tracks imaginable, if they run rubber track shoes like T48...and a fair number of them do. Examples:






Panda Plastics has a set of worn T48 and a set of desert-abraded T51, but I'd rather not spend another additional $22-30 plus shipping for tracks for this beast. I have a set of T48 in stock, and can use a Dremel with steel cutting burr to wear down the track shoe:





Looks nice! But do I want to spend hours doing another 158 or so track shoes? That's the question. And I haven't decided. Steel tracks are also a common feature, and they don't wear down much but merely rust to a deep brown:





I've also got both T49 3-bar cleat and T54E1 steel chevron; even a few shoes of T62 steel cuff. And you can see that mixed pads of types aren't unusual. Nor is seeing them mounted backwards; in fact I've not infrequently seen whole sets of T48 mounted backwards. Just the sort of thing to drive an IPMS judge into a swoon... Got some thinking to do about this, especially since wearing down an entire set of T48 will be very time consuming and not something I should do while the wife is working down the hall in her home office.

Oh, and if you're feeling like tackling one of these yourself and really want a challenge, I am personally aware of at least three yarders in Oregon alone running on Canadian Dry Pin tracks...

[JCON]

Oh boy, I don't envy you on this one!!!

[Beekster]

Feb 4, 2021 14:06:38 GMT -6 JCON said:

Oh boy, I don't envy you on this one!!!

Indeed. At least I don't have to commit for a while yet.  Once I get Dullcote on the big subassemblies, that will have to set up for at least a couple of weeks before I can proceed with weathering the engine bay and front gears & brakes, and I need to at least get a good start on that before I mate the top deck to the rest of the hull.  So plenty of time to consider tracks.  I will spend some time next Wednesday beating up the rubber chevron pads and see how it goes. That's the day the wife is in her official City Hall office, so she won't be bothered by noise.

[Beekster]

The shape of things to come:




I got the Dullcote on the major subassemblies over the last couple of days, and that has set up hard enough to do a mock-up. It will cure for a couple of weeks before I do any weathering. As you can see, it barely fits in the small lightbox and that only with the spar angled over further than it should be. Several things are apparent: One, I will need to test-fit the brush guards that will go on the cab windows for clearance to the spar. Two, careful thought will have to be given to just when to glue down the top deck to the chassis and finish up weld seams, paint, and a spritz of Dullcote when that is accomplished. Three, equally careful attention must be given to how to tackle rigging this beast. I already know that the straw & tag lines, the smallest ones, will have to be run through their sheaves on the spar before being threaded onto the drums. One of them will also have to be run through the front superstructure cover before being spooled, too. Four, I still have work to do on the spar hinge and retention pins to make assembling it easier. And fifth, taking any more pictures like this will require me to set up my larger light box, despite the challenges I have in lighting the subject when I use that.