A 60mm mortar is been suggested as a system for the M1 tank:- a breech loading 60mm mortar has lots of applications (and I've suggested it as part of a possible IFV turret configuration), but for smoke screening I'd expand on Mr Meyer's idea of a Mk19 loaded with smoke rounds.
Rather than having this in place of the commander's AAMG I suggest that it be in a pod mounted either on the side of the turret or over the main gun, rather like how the Israelis mount M2HBs. Since the Mk-19 lacks dual feed the weapon would either use a mixed belt of ammo or be used exclusively for smoke laying. If the smoke round were based on WP the barrage would still have several uses. Rounds landed ahead of a friendly force can be used for screening. Since WP rounds also have anti-personnel and incendiary effects and produce an irritant/toxic smoke that penetrates many filters a barrage fired onto an enemy position will rapidly make it unoccupiable. In an urban situation the incendiary effect may not be welcome, and a non-incendiary smoke composition used.
The adoption of the OCSW will free many Mk-19s for use as smokeguns. It is also possible that a lighter weapon based on the OCSW but using 40mm ammo and belt feed could be made for lighter vehicles. A pod with a smoke laying machine gun (SLMG) could be mounted on MBTs, CEVs and selected IFVs. Multiple mounts maybe mounted on the vehicles of Smoke Platoons, allowing them to lay screens anywhere within a mile radius. Since the OCSW uses "cans" rather than a belt feed it should be possible to more easily reload a OCSW with WP grenades. These could be simple impact-fused projectiles.
For more limited conflicts the SLMG can be loaded with CS rounds.
Chartered Ammunition Industries of Singapore make a 40x53mm grenade round containing Red Phosphorus (RP). This should be suitable for the proposed application.
More Smoke Related Ideas
For at least the last thirty years it has been obvious that there was a high likelihood of our forces being involved in conflict in desert environments. Despite this in many fields adequate preparation has not been made. It has been 12 years since Desert Storm yet troops in Iraq and Afghanistan still lack many items of equipment in desert camouflage. One of the features of desert warfare is very long engagement ranges. Terrain offers little concealment other than the natural folding of the land. The latter often offer little protection from aerial observation. For these reasons a capability to lay produce large smoke screens is of paramount importance.
Most divisions have a Chemical company that may have up to four Smoke platoons. Additional platoons and companies may be provided by the Corps-level Chemical Brigade. A Smoke platoon will have 6 to 12 generator vehicles, organized into 2-3 squads.
Mechanized platoons use an M113 based vehicle, either the M1059 Lynx or the M58 Wolf. A platoon has seven vehicles divided between two squads. The M113 gives the Smoke platoon better protection against enemy fire and good cross country mobility.
Motorized platoons have the generators mounted on a HMMWV variant such as the Coyote. Depending on the type of company the platoon is from it will have 6 or 12 such vehicles. On suitable terrain the HMMWV can move at greater speeds if necessary. Being a lighter vehicle it is also easier to move by airlift or helicopter assets.
Currently, mechanized platoons are placed in Heavy divisions, and motorized Smoke platoons in lighter divisions. The role of the Smoke platoon means that it will often be positioned between the enemy and the forward combat units, so some degree of armour would be prudent, regardless of what sort of brigade/division the platoon is screening. It is also conceivable that a lighter vehicle may be more useful in certain situations.
There are two ways to achieve this. The first is for the Chemical company to have two Mechanized (M113) platoons and a Motorized (HMMWV) platoon. Alternately, each Mechanized Smoke Platoon would include a Light Section of HMMWV mounted generators.
The HMMWV and M113 both generate smoke in their wake. It would obviously be useful if a Smoke platoon had an organic capability to lay smoke some distance ahead of its location. If a WP round was produced for the Mk-19 then at least one vehicle in a section could mount such a weapon with a supply of such rounds. This would allow smokescreens to be laid onto any location within a radius of a mile (1600m). Another possibility is shown by these Jordanian HMMWVs mounting Chinese Type 62 107mm MBRLs. A WP Smoke round is available for the Type 63 and range is 8,500m. The Egyptians use dedicated Smoke-laying MBRL systems such as the 12 barrel 80mm D-3000 Walid and 6 barrel 122mm D-6000. One volley from the D-3000 can generate a screen 1000yds long at 2500m range that lasts up to 15 minutes. This can be built up and maintained by a slow rate of fire. The D-6000 has a maximun range of 6000m and creates a 400m screen with six rockets. Each Smoke platoon should include a "Long Range Section" mounting a suitable light MBRL system.
Divisional artillery can also be used to lay smoke at long range, and it would be prudent if some personnel in Smoke platoons had some training in directing artillery fires.
On this page he points out that the OPFOR training units use their Mi-2 Hoplite helicopters to lay smoke screens, a reflection of the same capability held by Russian equipped units. This is a capability generally ignored by the US military. One advantage of a flying smoke generating capability is that it can lay screens in areas that would not be accessible to ground vehicles. For example, it could provide much needed cover to an infantry unit attempting to assault a position in mountainous terrain. And it can do this with far greater precision than an artillery strike, since the pilot can see the progress of the infantry. Another advantage of an aircraft is its mobility. Not only can it lay screens to protect an advancing force, but it can also quickly move to other areas and lay "dummy" smokescreens to deceive the enemy as to the units real direction of approach. During World War Two experiments were conducted using fixed wing aircraft to lay smokescreens.
Elsewhere I have suggested an aircraft called a Shrike, essentially a military crop-duster with STOL capabilities. Such an aircraft has numerous applications for desert operations, including the role of airborne smoke layer. Another idea is for the use of UAVs to lay smokescreens.