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

The Used, Abused, and Humble Lionel 520 Box Cab

Lionel Set 11341 634 3410 6407 6014 6463 6059

6561 Cable Reel Car - Lionel Trains Library

Life Support Lionel 520

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

eTrain Article - Train Collectors Association

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

Lionel No. 700e Loco, 700t Tender, 716 Hopper

New to my roster 520 box cab locomotive

April 2023 Lloyd Ralston Gallery