We may have a few hours to see the sights in London before catching a train to Scotland. Are there lockers that can accomodate 3-4 medium suitcases at Gatwick?

There are no lockers, but there is left luggage facilities at both N & S Terminals:

Left Luggage South Terminal Arrivals - Open 24 hours
£6.50 per item per 24 hours or part thereof.
Telephone: 01293 502 014

Left Luggage North Terminal Departures - open 05:00 - 21:00
£6.50 per item per 24 hours or part thereof.
Telephone: 01293 502 013

The part I don't understand is that you want to visit London for few hours and then go back to Gatwick to catch a train to Scotland?

Why not take your luggage with you to London, store it at the train station and then catch a train to Scotland from London?

It's a 30-40 minute train ride from Gatwick to London, then it's the same to get back to Gatwick just to pick up your luggage and then you'll be going through London again when heading to Scotland.

See my point?

Gatwick is south of London

Scotland is way up north

Any train you take from Gatwick to Scotland will go through London.

Gatwick trains end up in Victoria station.

AFAIK, Edinburgh trains leave from Kings Cross station.

And there are left luggage facilities at Victoria & Kings Cross

OK - now I get you other thread where you asked about how long after your arrival to pre-book your train. We all answered assuming you meant the 30 minute train up to London -- NOT a 5 hour train to Scotland.

It makes <u>absolutely</u> no sense to travel LGW &gt; London &gt; LGW &gt; train to Scotland.. None -- at all.

Either fly directly to Edinburgh or Glasgow from LGW w/o going into London -- OR -- take the train into London, see some of the city, and then take a train from Kings Cross to Scotland.