An Cosantóir

| 27 How to construct a sub-surface OP (Observation Post) Many corps and units within the Defence Forces have to construct sub-surface OPs in order to observe their target while at the same time remaining unseen and undetected. Fire support teams, cavalry or infantry reconnaissance detachments or ARW teams can operate for long periods of time keeping eyes on target and gathering and sending back vital ISTAR (intelligence, surveillance, target acquisition, reconnaissance) to higher headquarters. Select the Site 1. The site must be no closer than 800m to the target. Any closer greatly increases your chances of being detected. 2. Check the backdrop: Do not use the top of a hill. The idea is the OP will blend in with the background and will not be easily noticed by anyone on the ground or in the air. 3. Comms Check: Before you start construction make sure you have secure comms. No comms? Find another site. Construction, replenishment and de-construction of the OP are carried out at night time in order to avoid detection. Remember to only have one entrance and one way in and out of the area so as not to have paths all over the place. Cover your pathway with local foliage to conceal from detection. Construction 1. Peel back the sod, dig to required depth and width, depending on the number in your team and how much equipment you have. Remember, you could be living in it for up to 72hrs straight. 2. Fill sandbags with clay for wall construction. Dump excess clay 500m away from site and camouflage to avoid detection. 3. Construct a shelf for your optical equipment. 4. Reinforce walls with sandbags. 5. Construct aperture and trap door for target observation. Roof There are five steps to constructing the roof. 1. Construct a frame: for roof construction use poles from 105mm camo nets for the frame. 2. Waterproofing: place a basha over the frame for waterproofing. Secure with tent pegs and bungees. 3. Place camo net over the basha. 4. Place chicken-wire over the entire roof and thread local foliage through the wire to conceal and blend the OP with the surrounding area. Chicken wire is the best way to avoid breaks and lines in the roof. The threaded foliage allows for a continuous appearance and optimum blending with the surrounding area. 5. Once roof is finished roll the peeled sod onto the sides covering the tent pegs and edges of the basha, camo net, and chicken wire. Remember, replenish local foliage only at night www.military.ie the defence forces magazine

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