Lionel 520: Why is there a cable reel on the sides?

Life Support Lionel 520

The Used, Abused, and Humble Lionel 520 Box Cab

Used and untested condition. As-is as shown.

Vintage 1956 Lionel Lionel Lines 520 O Gauge Box Cab Locomotive

Lionel 0 and 027

Boxed Late Lionel Set 11720

Genisis of the Lionel 520 Boxcab O Gauge Railroading On Line Forum

Auction Database 0206 IN - Stout Auctions

eTrain Article - Train Collectors Association

April 2023 Lloyd Ralston Gallery