smith197:
One thing i completely dont understand is the payload and how u work it out, if for example they ask you how much pallets you could load onto a 44tonne lorry 
Hi Scott,
To tackle the payload question, you need to know 3 things:
1.) The weight of the vehicle when it’s not loaded.
(aka: tare weight or kerbside weight or un-laden weight [ULW] )
2.) The maximum weight that the vehicle is legally allowed to weigh when fully loaded.
(aka: Gross Vehicle Weight [GVW] or Maximum Authorised Mass [MAM] )
3.) The weight of the cargo that you will load.
If you subtract the empty weight from the max loaded weight, the answer is the amount of (cargo) weight that the vehicle is allowed to carry. The max cargo weight is known as the ‘payload.’
Depending on the exact terminology used in the questions, the calculation is:
GVW - ULW = (max possible) PAYLOAD.
Can I guess that somewhere in the case study it gives the empty weight of the vehicle, and the weight that the vehicle is allowed to weight when fully loaded, and maybe the weight of the pallet(s) [cargo] to be loaded??
EG:
A vehicle has a GVW of 18 tonnes.
The vehicle weighs 8 tonnes when not loaded.
A (theoretical) palletised load consists of 1 tonne pallets.
How many tonnes (pallets) can this vehicle carry?
ANSWER = 10 X 1 tonne pallets, so the authorised payload for this (theoretical) vehicle = 10 tonnes.
Of course, the payload could be just one item that weighs 10 tonnes, such as a piece of machinery.
If the ULW + the PAYLOAD = more than the permitted GVW, then you’ll probably get busted for an overloading offence if you’re required to pull onto a weighbridge for checking by the police/VOSA.
Has this helped??