5.5-in ammunition box?

[Clive_Dakers]

C.224

Size: Length 24.7" Breadth 15.25" Depth 10.125"
Empty Weight 11 lb. 8 oz.

Used for:
3-in. Q.F. howitzer Smoke

Number Packed: 12
Gross weight: 144 lbs

4.5-in. B.L. gun Cordite W- 1st Charge

Number Packed: 6
Gross weight: 57 lbs

4.5-in. B.L. gun Cordite W- 2nd and 3rd Charges

Number Packed: 6
Gross weight: 90 lbs

5.5-in. B.L. gun 3rd and 4th charge

Number Packed: 6
Gross weight: 88 lbs

6-in. 26-cwt. B.L. howitzer 4-lb. 6-oz. 4-dr charge

Number Packed: 10
Gross weight: 80 lbs

M.L. 8-in. projector, Generators Smoke, No. 23

Number Packed: 12
Gross weight: 100 lbs

[Lynn Eades]

I passed my heavy trailer licence towing one (possibly this one)with a Mk5 Inter(national)