Peter Mugridge
Veteran Member
Articulated stock ( regardless of wheels - it actually had conventional wheels; you might be thinking of the MP51 Stock? ) was the answer - but @Peterthegreat beat you to it I'm afraid.Early examples of articulated stock using rubber tyres?
MA52 was the only type of articulated stock on the Paris Metro, although there was a later prototype - BOA001 - that was also articulated, however that never entered general service and was used in public operation only very sparingly as part of a test programme ).