• Steel Soldiers now has a few new forums, read more about it at: New Munitions Forums!

  • Microsoft MSN, Live, Hotmail, Outlook email users may not be receiving emails. We are working to resolve this issue. Please add support@steelsoldiers.com to your trusted contacts.

 

USAF Mobile Microwave Shelter

Trailboss

Well-known member
Steel Soldiers Supporter
1,577
137
63
Location
Norwood LA
The purpose of this post is to document information on this trailer-mounted shelter that was recently being surplused by the USAF. I’ve searched the net and found no information, so if anyone has photos, TMs, etc., please let me know.

I won one of about 9 of these mobile microwave shelters from Eglin AFB sold through GP in April 2019. GP identifies the shelters as “S/A Enclosed Utility Trailer.”

The trailer and shelter have no manufacturer identification sticker or tag, but the AF has assigned a unit number that is painted on the trailer tongue. That painted unit number is the only identification that I've found on the 6-8 shelters I inspected. One of the vent fans has a date stamped 1984 but I don’t know if that is valid for the shelter.

1560703_3082_161_0001.jpg 1560703_3082_162_0001.jpg 1560705_3082_160_0001.jpg IMG_1007.JPG

TRAILER
Tires are mounted on 4-lug 16” rims and are either 7.00-16 LT NDT, 6.50-16 LT highway tread, or 225/75R16 commercial tires, and a large majority of the tires were dry-rotted to some extent. One shelter had a wider tire mounted, but the sidewall interfered with the spring pack grease zert to the point that the sidewall may have been gouged. Tire pressure is recommended at 40-50 PSI as per stencils. None of the trailers had fenders over the wheels. The single axle is a 1 ¾ inch square tube drop axle with a sliding spring pack. The trailer does have lights and surge brakes, so it may road worthy, but there were reports of heavy swaying at speeds over 45-50 mph. The trailer lights and 7-pin plug are 12-volt.

There are 3 jacks on the trailer that swing up for towing, two at the rear corners to be used for stabilizers, and the tongue jack. There is also a swiveling wheel on the tongue that can swing up and lock for towing. The tongue jack has a base extension welded to it, and the one I bought could only allow the pintle ring to lower to 24 ¾” to the bottom of the ring. This level was actually too high to allow the ring to drop into my truck pintle hitch, so I will probably replace the jack or cut off the foot extension.

The surge brake also has a rotating lever in front of the master cylinder that may act as a break-away lever, as well as a parking brake. The system was dismantled on my trailer, so I could not verify this.
IMG_1018.JPG

The trailer is constructed of 5” channel iron, 4” channel iron for the tongue jack mount, and 1 ½ x 2 ½ in angle iron for the 4 corner braces under the box. The trailer dimensions are overall length 169 5/8” (not including the step bolted on the rear) and frame width of 83 3/8”. The overall axle width wheel hub to wheel hub is about 100.5” The aluminum rear step is attached to the frame with 9/16" stainless steel bolts and nuts.

I’m not sure what’s the purpose of the tall steel structure at the front of the tongue, but the top plate has 4 bolt holes, and may be a braced mounting point for an antenna mast.

1560706_45_258_0001.jpg

SHELTER
The shelter is attached to the trailer at 4 reinforced mounting points using a clevis-head bolt.

IMG_1012.JPG

The shelter dimensions are:

Outside box (not including the tiedown brackets)
Width 80 5/16”
Length 100 1/16”
Height 77 9/16”

Outside box (including the tiedown brackets) w/o clevis bolts & pins
Width 81 ¼”
Length 109 1/8”
Height 79”

Outside box (including the tiedown brackets) with clevis bolts & pins
Width 83" (other dimensions same)

Inside Box
Width ~75 ¾”
Length 96 3/16”
Height ~73 ½”

The wall thickness seems to be about 2”, constructed of aluminum frame and sheet. The only steel found on the shelter are the corner lift/tie down brackets and rings, some of the door hardware, roof access steps. Don’t know if the insulation is solid foam or fiberglass matt, or ?.

The floor is asphalt tile, with a floor drain with plug just to the right of the door.

IMG_1009.JPG

The air conditioner is a Friedrich UE08D11C 8000 BTU Uni-Fit Series Room Air Conditioner with Electric Heat, 115 volts, and the freon has been removed from all the units I inspected (removal certification notice in some of the shelters). The AC is still available for about $630 from Amazon as of May 2019.

1560703_3082_0_0004.jpg

There are two vents to either side of the AC, and the shelters had none or one or two tubeaxial fans installed. The one in mine is labled NSN 4140-00-018-6535, made by Rotron, and dated 5-17-84.

Different shelters came with electronic racks or cabinets, but all seemed to come with a communication wiring array mounted to the passenger side of rear wall, with a cable to the wiring connector pass-through mount on the passenger side wall (supposed to have an inside cover but mine was missing). A lift-up door on the outside provides access to the wire connection points. The top hinge on this outside door on my shelter was frozen, and the pop rivits were broken, so when I removed the 4 bolts securing the door, it fell off. I’ve seen at least 3 variations of the wiring panel on the passenger wall.

1560703_3082_0_0005.jpg 1560703_3082_0_0003.jpg

Power to the shelter enters through the access port commonly found on other shelters (3 variations have been seen). Connections on mine are 4-wire female threaded plugs. On the other side of this port on the driver side rear wall is a breaker panel (I’ve seen 2 types of panels). Power supply is 120 volt, 30 amp, single phase. Lighting is 3 fluorescent light fixtures along the front and side walls. Empty fiberoptic cable raceways also travel along the ceiling.

IMG_1033.JPG IMG_1006.JPG

The four corners of the roof are steel/iron with swiveling lift/tie down rings. Most, if not all of the shelters had 2 cables permanently mounted to the rings and interwoven loops formed at the middle for lifting. My shelter roof had a square patch sheet of aluminum in the middle, but there is no indication of roof access inside the shelter. This may be protection from lifting hooks or attachments hitting the roof during shelter lifts.

IMG_1022.JPG IMG_1023.jpg

Another penetration on the upper front driver side wall is a 90 degree copper or brass hollow elbow, which is closed on the outside. Two holes marked V (verticle?) and H (horizontal?) are directly below the elbow. These will have to be plugged as they will let in rain.

IMG_1028.JPG IMG_1030.JPG


More to come as I learn more....
 
Last edited:

m1010plowboy

Well-known member
Steel Soldiers Supporter
3,790
2,304
83
Location
Edmonton, Canada
I'd love to see the shielding cross-section. Copper / nickel 'chicken mesh' wire is what we're finding for early RF shielding in structures. We've also seen documents on 2" lead sheets on a roof but we'd never lift a trailer if we did that.

Real interested in seeing some manuals on this one. Thanks for sharing.
 

Jericho

Well-known member
1,180
61
48
Location
Landaff NH
Good luck, reach out to some Air Field Control Squadron Guys who may be on here. Air Force is notorious for buying things off the shelf since the early nineties, When something is turned in for disposal ROUTINELY the full Demil manual is followed . Hence the air con refridgerent removed. THE BAD news is the AF , unlike the army, SELDOM if EVER releases Tech Date to the public, ALL most all of it is at a minimum FOUO( for Official Use Only) and a lot is classified . Iam not familiar with that particular trailer , but would venture to say it was Air Field Command And Control assets, for the AF its reasonably new, We ran some very old STATIC mounted equipment, got our investment back lol, it was no doubt mobile equipment and was likely used in bare base, deployed field locations, or as gear if an upgrade was in the works , Maintenace was spotty on that type of equipment, It wasn't performed by aviation guys or to aviation standard. It was either done by the owning squadron or the motor pool special equipment section . Major mods would have been done by the MajCom depot, likely Warner Robbins GA if it was ever authorized Depot repairs , some of the more basic stuff like this got no depot support and was done locally, remember the equipment inside the shack and the trailer are different assets ! Probably as clear as mud guys
 

Weller

Member
220
7
18
Location
Kern County, CA
I have several shelters about the same size but this is the first I've seen one trailer mounted, thank you for sharing specs and photos!

Most of mine have data plates. If I see anything similar is on any of mine and will let you know.

If you haven't checked yet, you can also look at the caps and the 4 wire plugs for part numbers and manufacturers. Bendix and Glenair would be two makers from the 1980's.
 

Guyfang

Moderator
Staff member
Moderator
15,676
21,604
113
Location
Burgkunstadt, Germany
Good luck, reach out to some Air Field Control Squadron Guys who may be on here. Air Force is notorious for buying things off the shelf since the early nineties, When something is turned in for disposal ROUTINELY the full Demil manual is followed . Hence the air con refridgerent removed. THE BAD news is the AF , unlike the army, SELDOM if EVER releases Tech Date to the public, ALL most all of it is at a minimum FOUO( for Official Use Only) and a lot is classified . Iam not familiar with that particular trailer , but would venture to say it was Air Field Command And Control assets, for the AF its reasonably new, We ran some very old STATIC mounted equipment, got our investment back lol, it was no doubt mobile equipment and was likely used in bare base, deployed field locations, or as gear if an upgrade was in the works , Maintenace was spotty on that type of equipment, It wasn't performed by aviation guys or to aviation standard. It was either done by the owning squadron or the motor pool special equipment section . Major mods would have been done by the MajCom depot, likely Warner Robbins GA if it was ever authorized Depot repairs , some of the more basic stuff like this got no depot support and was done locally, remember the equipment inside the shack and the trailer are different assets ! Probably as clear as mud guys
You are very much right. This is a typical "off the shelf" buy. The give away, is the picture showing the "NSN". When the military buys off the shelf, they assign a temporary NSN. The first 4 numbers are for that kind of equipment. After that is a shorthand discription. Reason being, assigning a real NSN costs big bucks. Stocking parts, printing TO's, (technical manuals) and training folks for its use and upkeep, cost big money. Often, the provider, (not always the manufacturer) provides the technical manuals. When that happens, most likely you will never get them. They are the property of the equipment provider. Pictures 16 & 17 are Wave Guide connectors. So some kind of radar or radio waves were fed in through these connections. H&V are for horizontal and vertical. The shelter looks repurposed.
 

M1078MAN

Well-known member
Steel Soldiers Supporter
672
893
93
Location
SW Va, Roanoke County
Interesting. like above, a AC nav system or ils. For sure not tcs/acs, however could be re-purposed. the connections led me to satcom wide band,the army tubular fan lends credence to repurp.

whats the usar reg number 84 x, b, l, k ----
 

Weller

Member
220
7
18
Location
Kern County, CA
Well, you motivated me to get out and look more closely at one of my shelters (it's an S-280 B/G), so thanks for that. I had seen faded lettering on the side (Fort Huachuca, Ariz) but now I see lettering above that reads USSTRATCOM.

20190505_090847.jpg
 

Michael

Active member
1,348
24
38
Location
Fulton, MS
I’m not sure what’s the purpose of the tall steel structure at the front of the tongue, but the top plate has 4 bolt holes, and may be a braced mounting point for an antenna mast.

View attachment 763541

...
Probably an auxiliary mounting point for the hitch so it can be pulled by a bigger truck like a 2.5 ton.

The trailer is probably a short run commercially built trailer that won't have a TM.
The shelter looks like a S-280 but smaller by http://www.gichner.us/products.html . There is a TM for general shelter repair out there.

Most shelters have a data plate, you sure there isn't one under the white paint?
 

Trailboss

Well-known member
Steel Soldiers Supporter
1,577
137
63
Location
Norwood LA
Probably an auxiliary mounting point for the hitch so it can be pulled by a bigger truck like a 2.5 ton.

The trailer is probably a short run commercially built trailer that won't have a TM.
The shelter looks like a S-280 but smaller by http://www.gichner.us/products.html . There is a TM for general shelter repair out there.

Most shelters have a data plate, you sure there isn't one under the white paint?
While the bolt pattern on the tongue riser seems to fit the pintle/master cylinder bolts, the pintle ring height would be around 48.5 inches. The current pintle ring height matches the M44 and M939 series pintle hitch height of 30-35 inches, and possibly the M1008 CUCV.

Although it has been repainted several times, I can't find any signs that a data plate was ever attached to the shelter or trailer.
 
Top
AdBlock Detected

We get it, advertisements are annoying!

Sure, ad-blocking software does a great job at blocking ads, but it also blocks useful features of our website like our supporting vendors. Their ads help keep Steel Soldiers going. Please consider disabling your ad blockers for the site. Thanks!

I've Disabled AdBlock
No Thanks