Suggestions about the composition of a specialized urban combat unit vary considerably. In his article in Jane's Military Review, 6th Year 1987, SS Fitz Gibbon suggests a more heavily-armed and manned squad than conventional infantry. Swedish Urban infantry, on the other hand, seem to favour a fairly light order. Both arrangements have their merits.
Carlton Meyer has discussed conversion of ARNG divisions into urban units, and these are a good choice given the high unit cohesion and espirt that these units often have. Many National Guard personnel will have civilian skills or expertise that will be useful to an Urban combat unit.
Urban Infantry Platoon Structure. Three rifle squads armed with SAWs and M16 (though M4s would be more useful in confined spaces). One man in each squad has a launcher for anti-armour/ demolition fire. This may be a RPG2000 type weapon or more likely the SMAW. The rifle squads are intended to be (relatively) lightly encumbered so they are very mobile and can easily scale walls etc.
Weapons squad. This has three GPMG teams. These either fire in a support role or can be allocated to individual rifle squads to up-gun them for small unit operations. These would effectively be the three team squads described here. The weapons squad also has a launcher, most likely a Carl Gustav that is also used to lay down smoke and illumination rounds. It is possible that a SMAW could fill this role if a wider range of ammo was developed. A Thermobaric round would also be useful. The weapons squad would have handcarts to assist in moving ammo and weapons. These carts have plenty of handgrips so they can be manhandled over rubble. Some weapons may be mounted on wheeled carriages
Squad/individual equipment. Essential equipment is body armour, including knee and elbow pads and protective eyewear to defend against splinters. Gloves will also be needed, and Gunshields may be used. Respirator filters should be capable of protecting against domestic chemicals likely to be encountered such a chlorine. There should also be provided some simple method of protecting personnel from smoke inhalation. Various lightweight emergency smoke hoods are already sold commercially, and some of these may offer protection from riot agents.
Troops will need suitable camouflage clothing. Woodland patterns have no benefit in most urban areas. The grey, black and white "urban" pattern used by some SWAT teams is not appropriate for many of the world's urban centres. The pattern also needs to add browns and reds. Suitable off the shelf patterns include Advantage and certain Austrian or Italian patterns. Distinctive camouflage will contribute to the unit's esprit de corps as well as its efficiency.
Preferred armament would be short barreled variants of the M249 SAW and M4s. M203s should be provided with both HEDP and canister rounds since many urban combats are likely to be within the minimum range of the 40mm grenade. The Doorknocker Concussion round would be an alternative to the HEDP. In addition to the squad's M203s, all personnel should also have rifle grenades or rifle-hand grenades. The squad should also have available at least one shotgun for remote destruction of locks and hinges (underbarrel mountings for assault rifles have been developed). The Israelis have experimented with a door knocker rifle grenade- it is possible that shotgun slugs can be used to open doors that might be booby trapped. Explosive rounds for shotguns may supplement M203s.
Small unit communications may be increased by Mobile phone type communicators. It is possible that these can also be used as IFF, though likely that such signals will be blocked by the terrain.
Sewer keys to lift manholes may prove useful, and a unit should probably include at least one crowbar.
Powerful hand spotlights will be needed since the interior of buildings are often dark. Tactical ways of using these need to be experimented with. The Lantern Grenades I suggest at this page would also be useful.
As well as training with SWAT teams, urban infantry will probably benefit from training with fire department personnel.
An interesting SWAT trick is to carry a thirty foot length of one inch wide nylon strapping. This rolls up to nothing in a leg pocket (actually provides padding) and is useful to lift items, climbing, securing doors, and the like. The one inch wide, nylon strapping can be used to lift articles or lift/lower people. Each end of the strapping should be sewn into a loop through which a hand or boot can be placed. Such strapping can be quickly knotted with a technique that involves doubling the strap/rope and coiling one end around the other in a series of half hitches (running end passing behind the standing part of each coil). Pulling the other end results in a chain of overhand knots. Other uses will doubtless be found for this strapping. It can be used to pull open doors when a booby trap is suspected, for example. Urban infantry webbing should have legstraps and attachment points for climbing gear.
Man-portable lightweight ladders are another useful item for urban infantry. Telescopic or foldable ladders are sold for use by SWAT teams. Ladders may be made narrower than conventional ladders to reduce weight, but should still be wide enough that they can be used as a bridge between roofs. The top of the ladder should have hooks, and urban troops practiced in Fireman's "hook ladder" technique, by which a short ladder can be used to scale a multistory building.
The unit needs good engineer support, with an emphasis on demolitions and smoke laying ability. The anti-tank platoon of the unit should include several 106mm recoilless rifles in addition to any ATGW systems.
If every infantry squad takes its transport vehicle into action, the result will be a gridlock. Most units will be foot mobile, and a ratio of one armoured/mechanized battalion to every four of "straight leg" infantry has been suggested. Part of this battalion will act as a mobile reserve/fire brigade so should mount decisive direct fire weaponry.
In the famous Swiss manual, "Total Resistance" by Major H. von Dach Bern a formation for an infantry company operating in urban terrain is shown:- The dismounted company moves in a column of two files, the right file watching the left side of the street and the left the right. In the lead is a point unit of dismounted infantry and behind this a pair of tanks ( or Assault guns, SP-ADA cannon etc). Just behind the tanks at the head of the main column are the infantry heavy weapons (mortars etc). At the tail of the column is another pair of tanks, their turret guns aiming to the rear. In the middle of the column are two or three vehicles which carry portable barricades to temporarily block side streets. These also carry ammo, ladders and other special equipment. Dach Bern describes these vehicles in the centre as trucks but M113s could do the same job and be less vulnerable to RPGs.
Fitz Gibbon suggest that each infantry company should have a two vehicle "Armoured Recon" section or that the Battalion have a platoon of vehicles to provide an organic support force. The Urban formation would also include a "ferry unit":- armoured vehicles with troop carrying capability but no organic infantry. These are used to quickly move straight leg infantry; bring up reinforcements, supplies or special equipment and evacuate wounded and non-combatants. These may be the vehicles of the infantry that are operating dismounted in the column formation described above. The armoured battalion also has the division's mobile strike forces and siege engines. These include:-
M113s equipped with fire fighting equipment -these can also be used as water cannon. They would also need more lethal armament systems for protection against RPG armed infantry. Infantry Support variants of the M1 Abrams.
Infantry Support variants of the M1 Abrams will be organic to the division and equipped with diesel engines, close-in weapon systems, increased smoke laying capability and main gun ammunition suited for urban operations. The use of diesel engines allows infantry to operate in close proximity to the tanks without being effected by the high heat output of the gas turbines used on standard M1s. An existing proven diesel engine such as that used in the Challenger 2 could be brought "off the shelf". Switching to Diesel will change the fuel consumption of the M1 to around one mile per gallon, rather than the current seven gallons per mile of the current engine. The German MTU EuroPowerPack diesel was succesfully mounted in a M1A2 Abrams in 1997. Some of these vehicles may mount shorter main guns, 120mm Gun-mortars or 165mm demolition guns. Large numbers of M1 tanks (around a 1000) equipped with the L7 (M68A1) 105mm gun are still in service, and some of these would be well suited for conversion into "Urban M1s". At MOUT ranges the 105mm is just as effective as the 120mm, and a larger number of rounds can be carried. The L7 gun is a rifled weapon and can use HESH rounds that are well suited to urban warfare. Another useful peice of equipment would be a vehicle mounting a "cherry-picker". This can be fitted with sensors for reconnaissance and remote controlled weapons, allowing it to look into and clear an upper story room. The arm of the picker can also be used to position a ladder.
On the topic of siege engines there have been recent improvements in demolition capabilities with the introduction of new types of rounds for the 120mm gun. Up until recently the Abrams was only supplied with APFSDS and HEAT rounds. The introduction of the M830A1 MPAT with a proximity fused setting increased versatility a little. The 120mm family of ammunition now includes the XM908 OR-T (Obstacle Reducing) Projectile and a Canister round, both of which are likely to prove useful in urban operations. The 105mm family of tank ammunition already includes proven APERS (flechette), Canister, WP and HEP (HESH) rounds.
In addition to early versions of the Abrams the 105mm gun is also used on the M8 AGS and the MGS version of the Stryker. The latter is undergoing extensive and prolonged development problems, particularly with its autoloading system. Even if perfected it is likely to be a poor vehicle for urban combat, since the tires will be very vulnerable and the high mounted gun will create a large deadspace around the vehicle that will hinder its capability to engage close targets.
An airdropped or air-landed force will probably not have Abrams available for support in urban operations, so it will be useful to look at alternate systems.
Another idea is to mount infantry anti-tank/Bunker defeat launchers in armoured boxes on the sides or turrets of vehicles such as the M113 and Bradley. This would give every vehicle in the column a demolition capability. This could be done with the SMAW-D or AT-4, although a soft launch system would be better. Elsewhere I've discussed how pods of the 2.75" FFAR could increase the capabilities of APCs. These have successfully been launched from blind-ended tubes, which would reduce discomfort to dismounted infantry. Another idea would be to mount 60mm or 81mm Gun-mortars on light vehicles. Given the low velocity and projectile weight these would be more "house-breakers" than bunker busters, but should prove useful against most non-military structures found in urban terrain.. Such a vehicle would be similar in concept to the wartime M8 HMC or the various German tanks, armoured cars, assault guns and halftracks that mounted the 75mm L/24 gun for infantry support.
Moving up a level the M8 AGS would also prove useful to forces that lack Abrams support and will be a more practical vehicle for urban operations than the MGS (which is heavier, less well protected and cannot be airdropped). Another potential useful system is the 120mm Assault gun mortar, which has both direct and indirect fire capabilities.
Demolition guns are not the only form of siege engine that will be needed. Barricades and debris may need to be moved, so at least one vehicle in each column or platoon should mount a dozer blade or similar structure. These would also serve as a frontal shield for the vehicle.
There may be a requirement to break down doors or create breach holes without using gunfire. Generations of tankers have found that the main gun barrel and tracks are quite capable of this and that by hitting the turret traverse the whole wall and possibly the building can be brought down. Lighter vehicles may need specially constructed rams, as are used on the armoured cars used by the SWAT teams of some Police departments. Quick ingress to the upper stories of buildings is another useful capability to have. Mike Sparks has suggested a M113 mounted with the VAMP system. My personal feeling is that a ramp based system will allow more Soldiers to enter the building in a shorter time and will be more stable on steep or uneven streets. A possible system designed for SWAT use is shown here. Such a system would benefit from ventral and side armour to provide more protection to infantrymen and would most likely be mounted on a vehicle similar the M113 variants once used to carry the Lance missile.
The Author of the CAT article proposes that a company of such vehicles be available for attachment to any field force that needs them. Such a company might also be strengthened by Sappers mounted on heavy IFVs that can also serve as anti-infantry tanks to support the CATs. A platoon of 120mm Assault Gun mortars would also be useful for this force. If based on a vehicle such as the Bradley these could be used in a direct-fire MOUT role when necessary. The CAT idea could easily be adapted to an Abrams platform, though it would be desirable to fit a diesel powerpack. Russian sources claim that the destructive effect of the 120mm Mortar rounds used with their Nona-series weapons is on par with 152mm/155mm Artillery Shells. The Abrams CAT may serve a dual role, since I can see the vehicle resembling an updated version of the M728 CEV.
An A-frame mounted on the turret might negate the advantages gained by the shorter mortar gun tube but this capability could be retained by fitting the booms ot the hull, as is done for the AMX-13 based VCG vehicle. Such arms may be useful in the deployment of infantry ladders and a camera pod could be mounted on them to let the crew look into higher story windows or see a longer distance in close terrain. When not being used for urabn combat such an engineering vehicle would be a useful supplement to vehicles such as the Abrams Grizzly