Why is the Queen’s coffin lined with lead? How heavy is it, why is lead used - what happens to a body in one?

People are already lining up to see the Queen as she lies in state in London, more than 24 hours before the line officially opens.

Infrastructure is being set up, and security personnel are preparing for millions of people to line up to pay their respects to the late monarch.

Her coffin will be placed in Westminster Hall at 5pm on Wednesday 14 September, and will remain there until the morning of 19 September. Full details will be provided on Tuesday at 10pm.

The coffin is built of English oak and lined with lead, as is customary for members of the Royal Family.

But why exactly are royal coffins lead-lined?

Here is everything you need to know.

When was the Queen’s coffin built?

The Queen’s coffin, along with that of the late Duke of Edinburgh, is thought to have been built some 30 years ago by Henry Smith, a specialty firm that was founded in 1869 and closed in 2005.

“My understanding is that the Queen and all members of the Royal Family have coffins made while alive… so there is no delay, the coffin is there,” Matthew Lymn Rose, managing director of A W Lymn, The Family Funeral Service, toldi.

The casket was maintained by funeral director JH Kenyon Ltd, who previously handled funerals for King George VI and Winston Churchill, until the 1990s, when it was taken over by family business Leverton and Sons.

Director Andrew Leverton told The Times in 2018: “It is made from English oak, which is very difficult to get hold of.

“Oak coffins are now made from American oak. I don’t think we could use English oak for a coffin now. It would be too expensive.”

Why is Elizabeth II’s coffin lead-lined?

Members of the Royal Family are customarily buried in lead-lined coffins to help preserve the body for a longer period of time.

The lead fully seals the coffin, creating an airtight barrier between its contents and the outside world and preventing moisture from entering. The body can thus be preserved for up to a year.

The concept of lead lining may be traced back to the Victorian era, when it was required to protect bodies when they were laid to rest above ground in an airtight sealed coffin.

This was for the benefit of preservation of the body of the deceased as well as the public - the airtight seals would keep any obnoxious odours resulting from decomposition from escaping the casket.

Lymn Rose said: “Most people are buried underground. If you have a coffin vault or a family chamber in a church then that coffin remains above ground and open to the elements. A sealed coffin is very important.

“Coffins are normally sealed by screwing the lid into the sides but that does not form an airtight seal.”

The Queen’s final resting place will be the King George VI memorial chapel in St George’s Chapel at Windsor Castle, where her mother and father were interred, together with Princess Margaret’s ashes.

The coffin of Prince Philip will be moved from the Royal Vault to the memorial chapel to join the Queen’s.

How heavy is a lead-lined coffin?

Because of the usage of lead, the coffin is exceedingly heavy, and The Times reports that eight military bearers will be required to carry the Queen’s coffin on the day of her state funeral.

According to Leverton, whose firm has handled the funerals of the Queen Mother, Princess Diana, Princess Margaret, Margaret Thatcher, George Orwell, and others, state funerals see coffin bearers provided by the Armed Forces.

“We have to attend meetings and help with practices. There are practice coffins which are weighted appropriately. We are a relatively small cog in a very big machine.

Lymn Rose added: “The modern process would be to zinc-line [the coffin]. Zinc is much thinner than lead, and more malleable.

“I have never, in my 20 years, seen a coffin lead-lined. The process of zinc lining is more simple, less costly, less weighty,” he said.