Kara Walker's fountain installed at Tate's Turbine Hall

Kara Walker is the latest artist to grace Tate Modern's vast Turbine Hall, with a huge water sculpture set to be unveiled to the public on Wednesday.

Fons Americanus is a 13-metre high soaring fountain that rises from two oval basins filled with water.

Its form is inspired by the Victoria Memorial near Buckingham Palace but it is more a critique of the British Empire than a celebration of it.

Sculptures covering the monument include JMW Turner's 1840 Slave Ship.

Walker's take on Damien Hirst's formaldehyde shark The Physical Impossibility of Death in the Mind of Someone Living (1991) also features.

The figure of the Roman goddess Venus stands at the top of Walker's fountain, recast as a priestess from Afro-Brazilian and Caribbean religions.

Walker presents the artwork as a "gift… to the heart of an empire that redirected the fates of the world". She has signed the work "Kara Walker, NTY" or "Not Titled Yet", in a play on the British honours system.

Speaking to the BBC, she said that using the Victoria Memorial as inspiration "was almost accidental".

"On my way to the airport, we drove past it and I took pictures immediately as it's the sort of thing that gets my heart racing - allegorical figures on that scale. It took another six months before I thought that this was the kind of thing I should investigate further."

Silhouetted figures have often appeared in Walker's work

Walker is otherwise best known for her use of black cut-paper silhouetted figures, referencing the history of slavery in the US.

She said the work was "about power... and the ways power has been unequally distributive, the imposition of race, for instance, determining the fates of peoples".

There was a moment during the press launch at the Tate Modern when Kara Walker briefly lost her composure. We were promenading around her 13-metre Fons Americanus fountain at Tate Modern, when I asked: "Is there a bit of Disney in this?

"Oh! That's the problem with this space!' she exclaimed.

"You know… [it] gave me the heebie-jeebies initially. It's a public space but also a playground space. There've been swings in here; there've been slides in here. So I thought, it might have a little bit of the hutzpah of a Disney, but I would not like that to be the reference you go home with."

We know all about the curse of Strictly, but Walker was referencing the unspoken curse of Tate's Turbine Hall. It goes like this: a highly respected contemporary artist gleefully accepts the invitation to fill the cavernous space only to fail miserably. There have been notable successes, such as Olafur Eliasson's giant sun and Doris Salcedo ominous crack, but generally speaking the results have not been good.

Well, Kara Walker certainly hasn't failed. She is an exceptional artist with an impressive body of work going back to 1994 when she first came to public prominence, with her striking cut-out silhouettes confronting issues such as slavery and violence.

In 2014 she cemented her place at the art world's top table with a critically acclaimed, racially-charged, sugar-coated Sphinx sculpture in Brooklyn, New York. She proved she could do huge.

And Fons Americanus is certainly very large, filling the far end of the Turbine Hall. But for all its size it is oddly unimposing, which is quite a feat when you consider there's a lady at the top with water gushing from her slit throat and large breasts.

Maybe, if she was the only figure in the piece, it would have more resonance. But she is one of a sprawling cast of characters: some referencing art history, others, Britain's colonial past. The overriding themes are the horrors of the transatlantic slave trade and the connectivity of water.

It is a sincere work, packed with ideas and intellect - and, at times, humour. It is thought-provoking and intricate, but unusually for this most precise artist, it ultimately lacks the aesthetic clarity to make the sum greater than the many parts.

Kara Walker is at Tate Modern from 2 October 2019 to 5 April 2020.