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Doug_Kibbey · Posted: Sat Mar 04, 2006 10:21 pm Post subject: Re: T-28 Photos

Thanks for posting that, Don...I had no idea how that "tow it's own track" thing would have worked, but now I get the idea.

This looks like a big PITA to install/remove.

Dontos · Posted: Sat Mar 04, 2006 10:26 pm Post subject: Re: T-28 Photos

All this talk of T28 has my interest up. I'm wondering if the detatchable outer track is SN matched to the vehicle that it was produced.

I went nosing around the T28 today and the outer L & R track assemblies match SN's but in the short time I had, I couldn't find anything similiar on the 'inner vehicle'

Buq-Buq · ***Power User*** Offline Joined: Mar 04, 2006 Posts: 86

Dontos:

Hey, cool pictures. I've never seen those before.

Obviously, the problem in the lower photo is that they are attempting to put it on the wrong side!

Wink

Anyway, for those of you who aren't familiar . . . what you don't see on the upper photo is the guys with ropes that walk behind the entire 'trailer-track assembly' to stop it colliding with the towing vehicle. For some reason, the 'trailer-track assembly' was not attached with a towbar, but with tow cables; this necessitated a human-powered friction-braking system. Capstans were bolted to the sprockets of the outer track assemblies, and ropes wound 'round the capstans. A crewman (or two?) would then walk behind the entire train, applying friction to the capstans as-needed to stop the entire 'trailer-track assembly' from ramming into the towing vehicle when on a slope. Since the maximum vehicle speed was only 8 miles per hour (and practical speed probably much less), this isn't as big a problem that it seems Ã¢â‚¬â€? although I imagine that you wouldn't want to do that for any great distance!

There are a couple photos in the Hunnicutt book showing the whole thing rigged for towing, and you can see the 'brakemen' at their positions. It says that an inexperienced crew took 4 hours to remove the track assembly (and another 4 hours to put them back on) on their first try; by the third attempt, they had it down to 2 and a half hours each way. Ahhhh, that must have been the life: come in in the morning, take the tracks off a T-28. Have lunch. In the afternoon, put the tracks back on a T-28. Go home. Come in in the morning, take the tracks off a . . .

Mark

Doug_Kibbey · Posted: Sun Mar 05, 2006 1:26 am Post subject: Re: T-28 Photos

So, were the outer tracks driven when installed, or did they just free-wheel around to reduce ground pressure? That would seem to make little sense, so how did the drive sprocket connection work, dualie sprocket that bolted up or what?

Garry_Redmon · Posted: Sun Mar 05, 2006 1:27 am Post subject: Re: T-28 Photos

This is all great stuff and it's pretty obvious from the information supplied by Chirs_C and Mark that I will have to make a change to my web site. I guess it will be c. 1975-1977 now.

I also regret that a unique piece of equipment like that will never be a runner. Since it has been sitting outside as a derelict and now a monument tank for 60+ years, that chance is probably zero.

JeffStringer · ***Power User*** Offline Joined: Jan 24, 2006 Posts: 637

Obviously, the problem in the lower photo is that they are attempting to put it on the wrong side!

No ... that 'side' is just standing by, the left side is already installed.

Pretty cool pics!

bsmart · Posted: Sun Mar 05, 2006 1:46 am Post subject: Re: T-28 Photos

"So, were the outer tracks driven when installed, or did they just free-wheel around to reduce ground pressure? That would seem to make little sense, so how did the drive sprocket connection work, dualie sprocket that bolted up or what?"

Looking at the picture above of the outer units being towed the drive sprockets appear to have a nub that extends outboard of the gear wheel. I would assime this either interlocks into the drive sproket of the outboard unit or is a hub cover for the connection points.

Buq-Buq · ***Power User*** Offline Joined: Mar 04, 2006 Posts: 86

Doug:

Regarding your question about whether the outer set of tracks were powered or not, I think that Mr. Smart has probably got it right. In the view of the inner sprocket on page 69 of "Firepower", there appears to be a coupling for the outer sprocket. I bet that you would remove the plate over the sprocket on the outer track section and join/disconnect the sprocket connection there, just like a normal final drive.

Perhaps Dontos could give us a bit of a confirmation, by tapping on the plate over the outer sprocket? and verifying whether it looks removable?

Mark

Doug_Kibbey · Posted: Sun Mar 05, 2006 3:31 am Post subject: Re: T-28 Photos

Thanks, Mark...I have to use some imagination..."Firepower" is not among the three Hunnicutt's I own, but even even in the grainy shot above it appears the inner sprocket has some protrusion on it. I assumed they just bolted up, or maybe there's some spliney thing that I can't make out.

It looks like a real nightmare to have seriously considered doing anything with. Decent looking design for a problem that would likely have had better solutions had it needed to be employed.

Roy_A_Lingle · Posted: Sun Mar 05, 2006 4:52 am Post subject: Re: T-28 Photos

- JeffStringer

Obviously, the problem in the lower photo is that they are attempting to put it on the wrong side!

No ... that 'side' is just standing by, the left side is already installed.

Pretty cool pics!

Go back and look at the photos of the tracks sections parked next to the building. The outside of sections are connected to each other. When the outer sections are linked together, the inside becomes the outside of the trailer. When the crew wants to install them, the tank is driven up and along side the trailer unit where the outside edge is linked to the hull and then becomes the inside edge. As the tank with one edge linked up is moved away for the other single section, support pipes are set up to keep it up right and not fall over. The individaul track sections are top heavy along their out side edges due to the armor plate along that side. Linking their outside edges together to form the trailer helps control the un-balanced sections.

Sgt, Scouts Out!

Jinx · Posted: Sun Mar 05, 2006 7:01 pm Post subject: Re: T-28 Photos

This page has 13 photos of the T28, some of them close-ups. Maybe of interest to some of you?

www.naritafamily.com/S...age_01.htm

Doug_Kibbey · Posted: Sun Mar 05, 2006 10:00 pm Post subject: Re: T-28 Photos

- Jinx

This page has 13 photos of the T28, some of them close-ups. Maybe of interest to some of you?

www.naritafamily.com/S...age_01.htm

I'd seen his site before, well worth visiting to view his models as well. Some excellent AFV stuff in additon to aircraft:

www.naritafamily.com/S..._frame.htm

Jinx · Posted: Sun Mar 05, 2006 11:05 pm Post subject: Re: T-28 Photos

- Buq-Buq

Anyway, for those of you who aren't familiar . . . what you don't see on the upper photo is the guys with ropes that walk behind the entire 'trailer-track assembly' to stop it colliding with the towing vehicle. For some reason, the 'trailer-track assembly' was not attached with a towbar, but with tow cables; this necessitated a human-powered friction-braking system. Capstans were bolted to the sprockets of the outer track assemblies, and ropes wound 'round the capstans. A crewman (or two?) would then walk behind the entire train, applying friction to the capstans as-needed to stop the entire 'trailer-track assembly' from ramming into the towing vehicle when on a slope. Since the maximum vehicle speed was only 8 miles per hour (and practical speed probably much less), this isn't as big a problem that it seems Ã¢â‚¬â€? although I imagine that you wouldn't want to do that for any great distance!

I cannot imagine this would be a lot of fun if the vehicle was going downhill.....!

Buq-Buq · ***Power User*** Offline Joined: Mar 04, 2006 Posts: 86

Jinx:

Great pictures of the T-28 on that site. You can see the various pieces that we've been taking about, fitted up in combat trim as the display at Fort Knox shows. In picture #416 you can see the capstans mounted on the upper right hull, just forward of the commander's cupola, and in picture #408 and #409 you can see what I suspect is the plate that you would remove to couple/uncouple the outer track drive from the inner track sprocket [drive].

In the picture that Tumbleweed posted, you can see the capstan mounted on the outer sprocket, as well as the rope that was used by the brakeman for that side.

And, yeah, Jinx, I imagine that hitting a downslope Ã¢â‚¬â€? no matter how slight Ã¢â‚¬â€? would not be a good time if you were a brakeman on that baby. Presumably this entire get-up was designed for use over VERY short distances; longer distance travel would require a serious lo-boy transporter (see earlier sections of this thread).

It's odd that they didn't just use a heavy-duty towbar.

Mark

Roy_A_Lingle · Posted: Mon Mar 06, 2006 10:50 am Post subject: Re: T-28 Photos

- Dontos

All this talk of T28 has my interest up. I'm wondering if the detatchable outer track is SN matched to the vehicle that it was produced.

I went nosing around the T28 today and the outer L & R track assemblies match SN's but in the short time I had, I couldn't find anything similiar on the 'inner vehicle'

Hi Dontos! Hi Folks!

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