Bert Coules wrote:
Most of my house is lit by ceiling-mounted triple spotlights which
use 40W R50 bulbs. Recently, three bulbs in the same position in one
particular fitting have blown within a short time of being fitted. One
lasted about thirty minutes, one almost three hours, the third
survived into the next day. I've checked as much of the unit as I
could without wholesale disassembly and found nothing obviously wrong.

All three bulbs came from a DIY shed multi-pack. Though it seems
unlikely, is it possible that there was something faulty about a
whole batch of them? Failing that, what else could cause this problem?

Many thanks, and a happy and healthy new year to one and all.

I've got those in my office. They never seem to last very long.