Military S-250 Shelter Conversion
- Thread starter rlrenz
- Start date
rlrenz
Explorer
Getting back to the S250 -
The most common lighting in these shelters was a 20 watt fluorescent equipped with a starter instead of a ballast. The lights had a curved translucent shade to diffuse the illumination. If you want to use only these fixtures, you will have to salvage them from a junk shelter, or make your own - they are unique to the Army and have a source code that shows they are supplied by the Army. IF you need any of the translucent diffusers, lottsa luck - they are also shown as being supplied by the Army. The other drawback is that they hang down from the ceiling about 4". This isn't a problem if you have an 8 ft ceiling, but with an interior height of only 64", an inch becomes critical - which is why I used LED fixtures in my 250.
The military stencils these shelters "Do not forklift" very clearly - yet many of the shelters have been damaged by forklifts. The problem comes from the combination of a fairly thin skin over a welded frame - if you only lift under the frame sections, you are OK, but if you miss, you have a problem. The military supplied a combination lifting sling and tie down assembly for the shelters, thankfully, these are still floating around on EBAY. You can tie a shelter down with ratchet straps as well.
If you get a shelter that has been used for a storage building by someone, the lifting rings and base anchor shackle might be missing. The base clevis looks a little like an M151 front lifting shackle, but the shelter shackles are more heavily made. If you install a shelter on a truck bed, you can replace the shackle with an angled mount and just run a bolt through the shelter lug. The upper lifting rings are only needed if you plan to hoist the shelter or use the rings to tie down the shelter.
The S250 shelters have been grafted into many different vehicles and trailers - they are a bit long for the old standby M37 3/4 ton truck - the correct shelter for the M37 is actually the S140, which is shorter than the S250. The 250 was designed to slide into the 1 1/4 ton truck, and it will fit a standard 8' box civilian truck if the wheelwell spacing is more than 49". I've also seen them in M105 2 1/2 ton trailers, and also slid into an M35 2 1/2 ton truck.
The most common lighting in these shelters was a 20 watt fluorescent equipped with a starter instead of a ballast. The lights had a curved translucent shade to diffuse the illumination. If you want to use only these fixtures, you will have to salvage them from a junk shelter, or make your own - they are unique to the Army and have a source code that shows they are supplied by the Army. IF you need any of the translucent diffusers, lottsa luck - they are also shown as being supplied by the Army. The other drawback is that they hang down from the ceiling about 4". This isn't a problem if you have an 8 ft ceiling, but with an interior height of only 64", an inch becomes critical - which is why I used LED fixtures in my 250.
The military stencils these shelters "Do not forklift" very clearly - yet many of the shelters have been damaged by forklifts. The problem comes from the combination of a fairly thin skin over a welded frame - if you only lift under the frame sections, you are OK, but if you miss, you have a problem. The military supplied a combination lifting sling and tie down assembly for the shelters, thankfully, these are still floating around on EBAY. You can tie a shelter down with ratchet straps as well.
If you get a shelter that has been used for a storage building by someone, the lifting rings and base anchor shackle might be missing. The base clevis looks a little like an M151 front lifting shackle, but the shelter shackles are more heavily made. If you install a shelter on a truck bed, you can replace the shackle with an angled mount and just run a bolt through the shelter lug. The upper lifting rings are only needed if you plan to hoist the shelter or use the rings to tie down the shelter.
The S250 shelters have been grafted into many different vehicles and trailers - they are a bit long for the old standby M37 3/4 ton truck - the correct shelter for the M37 is actually the S140, which is shorter than the S250. The 250 was designed to slide into the 1 1/4 ton truck, and it will fit a standard 8' box civilian truck if the wheelwell spacing is more than 49". I've also seen them in M105 2 1/2 ton trailers, and also slid into an M35 2 1/2 ton truck.
rlrenz
Explorer
Earlier, I'd mentioned that I had installed LED ceiling lights - I finally remembered to take a photo of the end result. They throw an amazing amount of might, and all with only 1.5 amps at 12 volts. As you can tell, I like thinwall conduit - it makes for a very nice job when it's correctly installed.
The open panel on the right is the old power inlet panel that also had the various phone lines that entered the shelter as well. I gutted it, and modified it into a circuit breaker panel that also has the old 24 VDC transformer/rectifier (to run the fans), and a 12 volt supply for the LEDs.
The open panel on the right is the old power inlet panel that also had the various phone lines that entered the shelter as well. I gutted it, and modified it into a circuit breaker panel that also has the old 24 VDC transformer/rectifier (to run the fans), and a 12 volt supply for the LEDs.
rlrenz
Explorer
Thank You.
I had been planning to make the correct fluorescents from scratch, but I eventually realized that They weren't needed. I'd run into a website that specialized in LEDs, and these priced out at about the same as the bits and pieces to make fluorescent lights. As I said, they are a lot shorter, so I gain another inch or so of headroom. My meter showed 1.55 amps for the whole thing, so they could even be powered by a small battery with a solar charger. This was also a test to see how these same LEDs would work in my medium ambulance - for instance, in place of the fluorescent over the action station, or over a reading area (AKA the squad bench).
rlrenz
Explorer
Today's project was sealing the power inlet panel. When the military cut the hole for the pass-through portion, they weren't as fussy as I would be - the hole was at least 1/4" larger than the panel on every side. I had thought about this project for a long time, including thinking about making an aluminum cover plate to take up most of the slack - then I remembered aerosol foam insulation - the stuff that comes in a can for about $5 or so. I picked up a can, masked off everything except the gap, and filled the gap. This morning, I used a thin blade to trim the overflow, then ran a bead of urethane caulking around it. I'll do the final cleanup tomorrow, then spray some OD green on it. Done deal - finally!
I've also been hauling all the misc. odds and ends out of the shelter that have accumulated - wire, connectors, terminals, a Riv-Nut puller, crimpers, socket wrenches I've been looking for a long time, pencils, tape measures, and about 2 cubic feet of "whatever...". It's getting roomier by the day....
I debated using a voltage dropping circuit to run the LEDs from the existing 24 VDC supply (left over from it's military time - it now only feeds the cooling fans), except the military power supply pumps out unfiltered and unregulated DC. I bought a $9.99 LED power supply from Amazon rated at 12 VDC and 4 amp output - since the lights only pull 1.5 amps total, I'm not too worried about a smoke run (http://www.amazon.com/gp/product/B003WJ218U/ref=oh_aui_detailpage_o05_s00?ie=UTF8&psc=1). It fit nicely into my circuit breaker panel, and works fine. The wiring is set up so it could be supplied from a vehicle battery, or from a dedicated deep cycle with a roof-top solar charger. With a 1.5 amp total demand, a charged deep cycle battery would probably handle this easily for a weekend.
I've also been hauling all the misc. odds and ends out of the shelter that have accumulated - wire, connectors, terminals, a Riv-Nut puller, crimpers, socket wrenches I've been looking for a long time, pencils, tape measures, and about 2 cubic feet of "whatever...". It's getting roomier by the day....
I debated using a voltage dropping circuit to run the LEDs from the existing 24 VDC supply (left over from it's military time - it now only feeds the cooling fans), except the military power supply pumps out unfiltered and unregulated DC. I bought a $9.99 LED power supply from Amazon rated at 12 VDC and 4 amp output - since the lights only pull 1.5 amps total, I'm not too worried about a smoke run (http://www.amazon.com/gp/product/B003WJ218U/ref=oh_aui_detailpage_o05_s00?ie=UTF8&psc=1). It fit nicely into my circuit breaker panel, and works fine. The wiring is set up so it could be supplied from a vehicle battery, or from a dedicated deep cycle with a roof-top solar charger. With a 1.5 amp total demand, a charged deep cycle battery would probably handle this easily for a weekend.
patoz
Expedition Leader
You do very nice, neat work! That says a lot about a man and his work ethics.
If I understand this correctly, the LED lights are 12VDC right? Are these household type lighting that works with a low voltage power supply or automotive, RV, Marine or speciality lighting? Do you have a link to where you purchased them from?
I have an ambulance almost identical to the Belafonte Reboot (Tom's) project that I'm converting to a camper trailer. I need to remove the existing halogen lights that hang down inside and replace them with something almost flush, in order to gain as much ceiling height as possible. I'm thinking I can get rid of the ones hanging way down completely, and replace the ones in the recessed area with the type you used, provided they put out enough light.
Thanks,
~ Pat
rlrenz
Explorer
The lights came from Super Bright LEDs (https://www.superbrightleds.com/mor...ed-round-dome-light-led-fixture-3w/1544/3514/) at a cost of $ 19.95 per each. I bought one as a trial, and then ordered 6 more. Not the cheapest out there, but at 3 watts each, the total string only pulls 1.55 amps, plus they are thin as well.
They are 12 volt. I tried them from 11 - 15 volts, and the light levels are the same. Amazon also sells a dimmer designed for LEDs (http://www.amazon.com/Lighting-Cont...1411136182&sr=1-6&keywords=12+volt+led+dimmer).
You might see a big difference in lighting when you replace a quartz halogen bulb with a LED - the light temperatures will be very different, plus you won't get the same sideways lighting that you have now from the drop-down diffusers, but the lighting at a working height should be pretty uniform. Also, remember you won't be doing surgery in the module, so light levels can be a bit lower than when it was an ambulance.
They are 12 volt. I tried them from 11 - 15 volts, and the light levels are the same. Amazon also sells a dimmer designed for LEDs (http://www.amazon.com/Lighting-Cont...1411136182&sr=1-6&keywords=12+volt+led+dimmer).
You might see a big difference in lighting when you replace a quartz halogen bulb with a LED - the light temperatures will be very different, plus you won't get the same sideways lighting that you have now from the drop-down diffusers, but the lighting at a working height should be pretty uniform. Also, remember you won't be doing surgery in the module, so light levels can be a bit lower than when it was an ambulance.
patoz
Expedition Leader
Thank you, you probably just saved me a lot of research. I've done quite a bit already, but with mail order you never really know what you're getting.
My unit has a total of eleven (11) halogen light fixtures like the ones you see in the picture, and each one also has a 'dim' mode which consist of a secondary incandescent bulb (similar to an 1156 bulb). There are the three down the middle, and four down each side in the recessed area above the diffuser lens. So yes, this is major overkill for a camper.
Here are two more companies that I have found while looking, and they come very highly recommended in the RV world. Both are reported to have excellent customer service with technician type people that you can talk to when you call.
My unit has a total of eleven (11) halogen light fixtures like the ones you see in the picture, and each one also has a 'dim' mode which consist of a secondary incandescent bulb (similar to an 1156 bulb). There are the three down the middle, and four down each side in the recessed area above the diffuser lens. So yes, this is major overkill for a camper.
Here are two more companies that I have found while looking, and they come very highly recommended in the RV world. Both are reported to have excellent customer service with technician type people that you can talk to when you call.
rlrenz
Explorer
Before I bought a set of LEDs, I bought one, then dummied up where it would go and what it would do. They shipped promptly, and the lights all worked perfectly. Check out their web site - they have many different 12 volt LEDs.
Mail order can be good news / bad news - I don't want to buy a sink, cooktop, or faucet until I can physically see one - The prices are high enough that I want to make haste slowly.
Who are the companies you mentioned?
Mail order can be good news / bad news - I don't want to buy a sink, cooktop, or faucet until I can physically see one - The prices are high enough that I want to make haste slowly.
Who are the companies you mentioned?
pappawheely
Autonomous4X4
I wanted a stainless sink for my camper and was surprised to find them at a good price at Ikea. http://www.ikea.com/us/en/catalog/categories/departments/kitchen/10473/
patoz
Expedition Leader
Sorry about that. They say the mind is the first thing to go when you start getting old. Hmmmmm!
Here they are:
http://www.oznium.com/
http://www.m4products.com/
rlrenz
Explorer
I looked at Ikea when I got started on my ambulance project, except their sinks were all larger than I could handle. I'll probably wind up with a bar sink or something similar. Also, the plumbing access will require a fairly shallow sink, about 5". Some of the ones I found were more than 7" deep.
rlrenz
Explorer
I finally remembered to bring my camera in and download some photos of what's been going on -
Here's the LED power supply installed in my reworked power panel - all the old telephone connections and the DC connector are gone. The LED power supply was installed in a rack made from some 1" aluminum angle and a backing plate - the rack was assembled with some 1/8" flat head aluminum rivets, and some tie-wraps hold the power supply in place. The 120 cord is connected to the panel's lighting breaker, and the output is spliced to the line feeding the lights.
The outside of the modified panel - I haven't labeled the circuit breakers yet, but the panel has a 0-150 VAC meter, a frequency meter, and a polarity-reversal indicator. The box hanging down from the panel is the original military 24 volt transformer - I replaced the stone age rectifiers with a $ 10 4-way bridge from Digikey. The smaller panel to the left is for the shelter's exhaust fan.
The exterior of the panel after I added some spray-can foam to fill the gap around the penetration. I also updated the power entry connector to one that I had that came with both the plug & socket
The panel after sealant was applied - masking tape plus a 3/8" washer for tooling worked well - after it cures, some green paint will finish it off.
Here's the LED power supply installed in my reworked power panel - all the old telephone connections and the DC connector are gone. The LED power supply was installed in a rack made from some 1" aluminum angle and a backing plate - the rack was assembled with some 1/8" flat head aluminum rivets, and some tie-wraps hold the power supply in place. The 120 cord is connected to the panel's lighting breaker, and the output is spliced to the line feeding the lights.
The outside of the modified panel - I haven't labeled the circuit breakers yet, but the panel has a 0-150 VAC meter, a frequency meter, and a polarity-reversal indicator. The box hanging down from the panel is the original military 24 volt transformer - I replaced the stone age rectifiers with a $ 10 4-way bridge from Digikey. The smaller panel to the left is for the shelter's exhaust fan.
The exterior of the panel after I added some spray-can foam to fill the gap around the penetration. I also updated the power entry connector to one that I had that came with both the plug & socket
The panel after sealant was applied - masking tape plus a 3/8" washer for tooling worked well - after it cures, some green paint will finish it off.