This idea originates from the merging of several sources. One is the old military joke
"The side with the simplest uniforms wins".
Another is a comment by a military re-enactor that of all the uniforms he had worn, Vietcong pyjamas were by far the most comfortable. There is nothing wrong with a soldier being comfortable if it allows him to do his job better.
I was also thinking about camouflage and reflected that most of a combat jacket is covered by webbing and body armour. In the book "Black Hawk Down" it is mentioned how distinctive the black flak-vests of Rangers were. Even ignoring camouflage considerations, wearing black in such a sunny hot-dry climate will contribute to overheating.
There are camouflage covers for body armour, but a far simpler and cooler solution is the camouflage smock. This is a loose baggy garment worn with suitably patterned BDU trousers and worn over the body armour but under the webbing. The BDU jacket is used for fatigue and garrison wear or can be used in combination with the smock.
Two of the most well known users of these smocks were the WW2 British airborne forces and the Waffen SS. The German smock was hooded and usually reversible. The British "Denison" smock had a full length zipper. Both were worn over standard woolen field/battle dress of a low visibility colour such as field grey or khaki. Both were initially produced due to the technical problems of printing camouflage patterns on wool, but smocks proved to offer additional advantages.
Let's consider the possible features of a modern smock:
The smock is a loose simple garment made of lightweight cloth. Its primary function is camouflage. Protection or heat retention is the function of whatever clothes are worn beneath. The smock can be rolled up into a small package, allowing the soldier to carry a spare smock or one in an alternate pattern. The smock should "fit like a potato sack" allowing plenty of room for air circulation and items worn underneath.
The smock will be of a simple cut -probably hooded with raglan sleeves and four to six pockets. The idea of placing the upper pockets on the shoulder/ upper arm region instead of the chest can be considered to allow access to contents when webbing is worn. For the same reason the chest pockets would have vertical zippers, like French combat jackets, so the contents can be more readily accessed when suspenders are worn. Being a very simple garment the smock should be very cheap to produce.
The smock may be an over the head design, like the SS models, or have a full length frontal opening. The latter may be a zip, although some Special forces soldiers prefer to replace zips with velcro. It maybe that cold weather smocks are kagoule-style while temperate and hot weather patterns have full openings.
Smocks can easily be made reversible. A general purpose smock might have on one side a dark pattern such as "woodland", British DPM or Mossy Oak Break-Up. On the other side would be a lighter pattern such as Advantage. A "winter" smock would have one side of white and the other an autumn or snowless pattern such as Realtree Hardwood or Mossy Oak Forest Floor. A desert smock could have a day pattern on one side and night camouflage on the other. More likely is that a "night pattern" smock is worn over a day smock to provide extra warmth as well as camouflage. The introduction of smocks could be used to cheaply introduce newer, more effective patterns.
It is possible that the smock can be made from frame retardant Nomex or the cotton treated with Borax. Smocks would allow Nomex field wear to be introduced for soldiers without having to replace the vast existing stocks of BDUs.
Some manufactures are experimenting with materials that can be worn all the time but still offer comprehensive NBC protection. Such materials are likely to be too expensive for garrison wear, so making them as smocks that are only worn in the field when there is a NBC threat would be more practical.
The smock would be a field/theatre wear item so soldiers can add pieces of netting and frayed cloth and loops of elastic to hold foliage and improve the smock's effectiveness.
Being made of a thinner cloth and worn over the body armour, smocks may be more prone to damage than a standard BDU jackets. Soldiers will not be punished for having a smock that gets damaged unless this damage is not repaired. Patches and random stitching on the smock will probably improve its camouflage performance.
What does a soldier wear under a smock, other than his armour? Basically, anything he likes.
If a soldier wants to wear a BDU jacket packet with his favorite SERE gear under a smock, fine. In warmer climates he may wear just a tee shirt or bush shirt, in colder several woolen jumpers, thermal underwear or a "Double P" tunic. Smocks can also be worn over raingear. In certain situations smocks may be worn over civilian clothes or Class A's. Most military vehicles would carry a couple of smocks which crew or passengers can use should they be ambushed
A smock in high visibility Lime green would be useful for disaster relief operations. Better still make the body part lime green and the hood and sleeves orange, so wearers are identifable as military personnel as well as visible. These smocks would be marked with unit numbers or relevent specializations such as "Medic". The reverse side would be camouflaged in the event the tactical situation changes. Such a smock would also be useful on airfields or for MPs on traffic control duty.
Suggestions
For "Green-temperate" and Jungle conditions I suggest a modified version of British DPM (Disruptive Pattern Material) instead of US Woodland Pattern. Main colours would be Green, Khaki and Brown with smaller areas of Dark Grey (eg, Graphite) instead of the full black currently used. This Hungarian pattern of Sand, Red-Brown and Light and Dark Green is a possible choice. Such a pattern could be created with existing screens and machinery used to produce Woodland. A beige rather than light green base cloth would be used and printed with brown, dark green and dark grey. On the reverse of this garment would be Advantage pattern or some other light, brown dominant pattern which will serve in most other temperate conditions. Such a pattern could be created with Woodland pattern screens, but using a beige base printed with brown, slate grey and charcoal. In jungle conditions camouflaged Mesh "bug suits" are a possible alternative to combat smocks.
Winter smocks would be White, with the occasional sprinkle of Dark Grey. On the other side would be Realtree Hardwood or Mossy Oak Forest Floor. This smock might be a pull-over design with knitted cuffs.
Many Middle Eastern countries use a desert pattern that is simply British DPM without the green added. Not only would this pattern be simple to produce, but is also very effective. Lack of the green patches makes the khaki areas bigger, increasing camouflage effect in open terrain. Once again I'd replace black with dark grey. British Army desert pattern omits the black too, so it is DPM with just sand and brown. However, current three-colour desert pattern seems to work well enough I'm not sure that having a desert smock lined with a dark nightsuit pattern would be very comfortable and may increase the likelihood of overheating. An additional night smock may be more practical since it will help insulate from the chill of the desert night. Special Forces, ASI Direct Action Teams, Snipers and other units may make use of special night camouflage coveralls. These would have a dark pattern such as that of the desert suit on one side and on the other a lighter night pattern such as "Subdued Urban" or "Sky Blue" pattern. The side most appropriate for the level of illumination and background is worn outer most. This may be the same garment worn at night with desert dress.
Smock features.
Smock should have a hood that rolls up into the collar and is secured with velcro.
Epaulettes should be fitted for use in conjunction with rank sliders.
Chest pockets should be of the "Napoleon" type, with vertical zips for easy access to contents when suspenders are worn.
Pockets fitted to the upper sleeve could also be included. These should be the same size as the chest pockets of the current BDUs. Spaces should be left in the top stitching so that items such as pens are easily accessible.
Cuffs should be adjustable, possibly along the lines of those of the M65 jacket. The snow-smock may have knitted cuffs.
The jungle smock would have detachable sleeves, and these can be replaced by insect-proof mesh sleeves.
There should be large lower cargo pockets. Some Soldiers don't like these, others can't live without them. Don't use them if you don't want to, but they should be present.
Trousers and Jumpsuits Smocks can be worn with BDU trousers, but an alternate idea is to also produce a loose fitting "field trouser". This would be similar in cut to pyjama leggings or track bottoms, but would have cargo pockets and canvas reinforcements at the knee and seat. Special pockets for items such as survival kits or pocket knives or multi-tools can be incorporated. The waist would be drawstring or elasticated, but there would be provision for using a belt, braces or even a bib front for those would desire such things. Cut would be loose enough to fit over knee and shin pads, and the desert pattern trousers would be extra baggy so they behave much like arab garments. For some applications, such as the Nightsuit a jumpsuit may be used instead of smock and trousers. Such a jumpsuit will be loose fitting and have two zips that run from collar to ankle so the garment can be easily donned or removed
Captain John Wilson has proposed the idea of an "Adaptable Combat Uniform" (ACUs): I advocated long ago going to a straight khaki BDU (no pattern) and khaki TA50 (webbing) gear. Then, develop a temporary "spray-on" ink set (similar to Bowflage) and camouflage pattern templates for various regions. When the soldiers deploy (to the training area or to the theater of operations), they spray on the template (color-by-numbers with some adult supervision) that is dictated by the region (METT-TC). Once they redeploy, they treat the BDUs with a solution to cut the ink and wash them in a standard washing machine. The inks should work on BDU cloth as well as TA-50, gortex, etc.
PW: A better pattern of camouflage could be made using the stencils already in existance for the current Woodland pattern. Use a base cloth of khaki, and for woodland pattern print this with Dark Green, Brown and Graphite Grey. For a more brown based pattern, use the same stencils and base cloth but replace the Dark Green dye with mid-grey, so the pattern is Khaki, Mid-grey, Brown and Graphite. The same khaki cloth on its own would make be very effective in desert conditions. If desired patches of Medium brown or Grey can be added.
As an alternative to John's DIY idea, large stockpiles of khaki smocks or field dress could be built up and screen printed with the appropriate colours prior to shipment to the unit.
Many thanks to Jade Geko for these interesting links on clothing and camouflage.:-