Found this on ARSSE forums although it is a few years old now but this covers AP activities
Assault Pioneers were (are) a vital asset to any CO or Battlegroup. Their duties include;
• Demolition (inc explosives using electric or flash initiation)
• Field defences (plant or manual)
• Minelaying (clearing, recovery or disposal of)
• Water purification (making it fit for their BG to drink, an often neglected art in this day & age)
• Bridgelaying (usually in support of RE)
• Watermanship (The army's word for boat handling or rafting)
They can also expect involvement in;
i) Search (Urban, Rural, Veh or body)
ii) Forward Recce for RE (ie where to throw a Bridge, fascine or trackway)
iii) Just about anything their unit throws at them.
Modern Infantry Battalions are unlikely to have an establishment for Assault Pioneers therefore manning & getting the right calibre of soldier is a problem (an OC told to provide XX men will send knackers if he can get away with it). Initial training is conducted in house but leads to B2,B1 & W/O courses @ Minley Manor & RSME.
An Assault Pioneer sect/plt starts life as a bunch of misfits & bottlewashers but soon becomes resourceful & able to use its initiative. I recall having to clear a helipad in the jungle using little more than hand tools & the bare minimum of demolition accessories. We managed to fell (HUGE) trees by making shaped charges (enabling us to place a small charge in the centre to bring them down) from compo tins & moving the timber with some virtually useless turfoil jacks to ensure the helipad would be ready on time.

