This is about signal processing in the first radar
Indeed, in the very first time of radar, the technology necessary to measure delay between transmited and received echoes wasn't avaible for EM waves. 
I think that these first type of CW radars weren't used for ranging, only for detection. 
Using only one sensor which emit and receive the CW signal you can't perform ranging. In a bistatic configuration, i.e. the transmitter and the receiver arn't colocated, you may perform rangin by imposing a constraint on the target's kinematic (for instance, constant speed) and integrating measurments over time. 
Using a network of sensor (so called multistatic configuration) you may perform "real time" ranging without having to integrate measurments nor imposing a kinematic model on the target's motion.

Direct answer : These early radar were used only for detection and not for ranging.