The N113 is a rear engined chassis, no doubt. But the engine is
mounted in a vertical-transverse position. In other words, the
engine position is similar to that of the Olympians.
On Scania chassii, the first letter denotes the engine position.
AFAIK, Scania only has rear engined models.
N = vertical placement, transverse driveline
L = tilted at 60 degrees to the left, longitudinal driveline
K = vertical placement, longitudinal driveline
The 2 or 3 digits that follows denotes the engine capacity and the
chassis generation.
eg.
113 = 11 litre, 3rd gen
94 = 11 litre, 4th gen
The last 3 character denoted the chassis type
eg.
CRB = single deck/coach, right-hand drive, normal floor
CRL = same as above but with low entrance
For the 4th gen chassii, only 2 characters are used
eg.
IB = intercity chassis
UB = urban chassis
UA = urban chassis, articulated