Contract is for 760 hours, for which you'll get basic salary plus £13.30 (ish) per block hour (from Jul 05) plus allowances. You can volunteer to work to 850 hours if you wish. As a volunteer you'll get ~£60 per credit hour for every credit hour you work over 81.5 per month. If you work over 760 you get basic/750 per hour plus a ramped up equivalent of the £60 per hour. Unlikely to get a contract for <760 hours in the current climate-especially on the 340