Switchgear Testing Co
of Trafford Park, Manchester.
Conducted switchgear-testing programme for the constituent firms (presumably part of AEI).
1934 A sixteen-element electromagnetic oscillograph was made for the company by Metropolitan-Vickers.
1934 The 3 switchgear manufacturing companies in the AEI group - BTH, Ferguson Pailin and Metropolitan-Vickers Electrical Co were jointly erecting a high power testing plant to handle rupture tests on the largest types of switches[1]