Very secure lock – but not if it’s like this.

This lock was fitted to a commercial premises. It is a Chubb 3G110 which is an excellent detainer lock. (Detainers are a bit like levers). This lock costs several times more than a normal mortise lock.

The lock was opened to change the detainers so it operated with a different key. It was immediately obvious that somebody in the past had removed all the detainers. In this condition the lock could be opened by any key that fitted into the keyhole – or even just a screwdriver or lolly stick. What would have been presumed to be a very secure lock actually had no more security than a garden gate latch.

chubb 3g100
Detainers missing from the lock case on the right. Detainers about to be fitted on the left.

New detainers were fitted to the lock and it now secure – as it was designed to be.

This lock is closely related to the Chubb 3R3F that we saw in a previous post. Access control system repair | Ross-Dean Locksmiths (ross-deanlocksmiths.co.uk) There are also other versions which use the same detainer system but with roller or spring latches.

On an unrelated subject, we’ve been called to open 3 separate Mercedes cars this week with keys locked in the boot. One of them was at 3am on the M5. Normally we might open one Merc in a whole year. Not sure why Mercedes owners are being more careless than usual at the moment.

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