Until 2008, only one piece of cabin baggage was allowed to be carried through security checkpoints at Gatwick. Now that restriction has been lifted, and you can carry two pieces, but they must still stick to the size limit of 56 cm by 45 cm by 25 cm. Sharp objects and gels and liquids in excess of 100 ml are not allowed to be carried through security checkpoints at Gatwick, either.
Pack odd-sized sporting equipment or instruments in your checked baggage, along with larger-sized liquid and lotion containers, sharp objects, tools and cutlery. Airlines are responsible for weight limits for checked baggage traveling through Gatwick.
You are never allowed to take flammable materials, fireworks, poison, radioactive material, magnets and certain chemical compounds in your hand baggage or checked luggage if flying from Gatwick. Consult the Gatwick Airport website's "Baggage Restrictions" page for a complete list of items that you are not allowed to take with you.
Gatwick provides storage lockers in both the North Terminal and the South Terminal for 24 hour intervals. If you have a long layover in Gatwick and want to spend your time unencumbered, this is a good option. However, you will have to check your bags through security again after picking them up.