Cable calc help please

[Doomed]

Doing an inspection on two workshops at the end of the garden.
Workshop one has 40A MCB feeding 6.0mm T+E to junction box on the inside of the house on back wall, then 6.0mm SWA buried to the workshop. Distance to workshop 20m.
If the run was all SWA I calculate this as OK (just - max load approx 41A?, size of cpc to be 6.0mm as zs 0.54 and u0 246) but with the T+E involved how does my calculation alter?
The second workshop has a similar arrangement with a 20A MCB and 2.5mm T+E and 2.5 SWA which I calculate as once again just being OK.
Both have fuse boards in the workshops.
I already know that the SWA is not glanded properly nor the armour earthed.
There are no other utilities to the workshops.

What are your views please.

edit: both SWA's are 3 core with one core being used as the cpc - one on line cable calculator said that for the 40A load 2 core 6.0 SWA was OK but 3 core 6mm SWA was not - this confused me

 

[IQ Electrical]

Assuming any bonding requirements are suitable (thinking TN-C-S and exposed-conductive parts in workshops) then I wouldn't be concerned at the CSA and length of run.

There'd be a code 2 for the lack of earthing to the SWA (both ends if it is the CPC, one end if there's a third core) and another code 2 if the manufacturers glanding requirements are not met.

 

[oxocube]

I believe some online calculators assume 3core cable is always a 3 phase circuit.

Do an adiabatic on the T&E to see if the earth is adequate.

 

[Richard Burns]

I agree, the cables are suitable for the application described.
SWA armour should be earthed by being properly glanded as IQ says.

For CCC calculate for the worst case section of the run, but they are the same anyway. Distance is not a problem in this case.
The three core cables are CCC for 3phase not single phase if one is the CPC then it is not (normally) carrying current.
Hope there is some RCD protection around.