Plumbing - Stopcock dont work

Had a plumber around to do some work.
He needed to turn off the water supply.

He tried the normal tap type stopcock where the water pipe comes into the kitchen (under the sink) but said the tap was frozen and unusable.

He then went out into the lawn and flipped a little metal hatch and used a big long metal 'yoke' to turn off the water.

I didn't think at the time plumber was around but I'm now worried that if we had a problem where we needed to turn off the water we wouldn't be able to due to the unusable stopcock.

Can I buy one of these long yokes to turn the water off from the lawn hatch ? If so, where ? and what would I ask for ?

Might be better in the long run to get a plumber in to fix your existing stopcock.

Your house obviously has an older type stop cock grate without a lockable cover- more modern combination meter and stopcock are not accessible without a special key, property of the local authority. You can get the stop cock key you require from most hardware stores, even Woodies might have them. They're not expensive. You should really look at having the undersink stopcock replaced- especially in case of an emergency.