I know First hand how devious Pikies are Went out to a commercial boiler where he'd been hit 3 times, taking 1,000 litres of red diesel
First time they disconnected the 10mm oil line from the tank & syphoned it from there, so the company built a steel box over it
second time they undid a 10mm straight coupling & syphoned of yet another 1,000 litres, so another steel box was put over the joint
the third & last time they drilled a hole in the BOTTOM of the tank, drained off about 90% of the fuel & then Jammed it with a stick, which was dripping (that was the only way the company knew they'd been hit again) so I was called out to install a new tank in a purpose built brick house
oh & this WILL put a smile on your faces, the company repaired the leak & filled the tank with water & red food dye!! & yes they were robbed again.... hope the thieving bast@rds engines all siezed up!!!!
Sensor systems do an alarm which seems to work, my advice DO NOT LOCK the tank, if they're going to steal it they will NO lock will hold on a plastic tank...what would you rather pay for £660 for 1,000 litres to replace the lost oil OR £1500+ for a new tank, the damage to the ground caused by leaking Fuel £thousands & THEN the £660 for the fuel
DON'T get me wrong personally I'd beat the B@st@rds with a baseball bat, but you have to way up the lesser of 2 evils, A good security light, a big barking dog, & well fenced, also OUT OF SIGHT OUT OF MIND,
but have heard of a horror story where the pikies were following the tanker around to see who would be the easiest to rob
you just cant win