The Cambria is another of Donal O’Kelly’s singularly imaginative plays which takes place on the high seas. His award-winning Catalpa (1995) retold the story of the 1875 voyage from New Bedford to Freemantle to rescue Fenians, and recently The Adventures of a Wet Señor took as its central incident the shipwreck of a Spanish Armada vessel and the fate of the survivor who washes ashore in Ireland in 1588. The Cambria is not a new play. It has had successful runs in New York and an Irish tour since it first appeared in 2005; but apart from a single night at Liberty Hall this is its first appearance on a Dublin stage.

One of O’Kelly’s hallmark framing devices introduces us to the play. In Catalpa the historical subject emerged from the frame of a contemporary writer in a barren bedsit trying unsuccessfully to make a film of the Fenian story, and his vivid recreation of the voyage for us. In The Cambria a dockside discussion of a contemporary incident in which a Nigerian asylum-seeker is deported from Ireland provides entry into the story of the inward journey Douglass made more than a century earlier.

A mysterious man is on board The Cambria as it departs New York for Queenstown (Cobh) in 1845. Mr. Johnson is a black man with a first-class ticket mistaken for a minstrel by a pampered, intelligent little girl, Matilda Dodd, who shares the next cabin with her bigoted father from New Orleans. The latter cannot abide proximity to a Negro and expects the social potocols in effect in the United States at the time to be enforced on the voyage. Instead of banishing the black man below decks, Captain Judkins finesses an acceptable reason for Mr. Johnson to switch places with a lady in a lesser cabin whose health is suffering during the voyage.

But Mr. Johnson is escaped slave Frederick Douglass, travelling incognito. He has just published his life story and fled America as a wanted man. The lady he has graciously accommodated onboard is a fiery abolitionist who quickly allies herself with his cause, as does Solomon, an able seaman of colour who knew Douglass in an earlier incarnation. The Captain asserts his authority over the upper-deck bigotry on board, and the acclaimed Frederick Douglass, orator and statesman, steps down the gangplank in Cobh to tumultuous applause.

O’Kelly’s plays tend to bravura multiple role-playing, usually by a single actor, namely O’Kelly. In The Cambria all the roles and sound effects are provided by the author/actor and actor Sorcha Fox. Among many others, O’Kelly plays both Douglass and the bigot, while Ms. Fox is both the abolitionist and the precocious youngster. They each play the Captain as the script requires. It is compelling to watch the rapid transformations made by the actors and hard to believe at times that there are only two of them in it.

Director Raymond Keane succeeds in controlling the demanding physical requirements of the play - the movement on stage is neatly choreographed. However Benbo’s production of The Cambria suffers, as earlier O’Kelly productions did not, from reliance on the repetition of a limited number of recognizable gestures in O’Kelly’s repertoire, and more importantly, little control of his use of accent. The latter flaw undermines the production greatly and makes audience engagement difficult to maintain. When actors must juggle multiple roles, the predominance of clear character signature must be airtight and unwavering, and two of the limited means of achieving this clarity are voice and gesture. (Scant use is made here of costume or props.) O’Kelly’s portrayal of Dodd, the New Orleans slave holder, begins with the appropriate drawl, but this manifests only sporadically, leaving him to rely instead on a demonic grimace to signify the character. Otherwise the slippage in accent wanders anywhere from Philadelphia to Manchester. Sorcha Fox exhibits far better vocal stability in all her characters; but when she and O’Kelly do Captain Judkins in different voices it is simply confusing. Fox’s little Matilda is excellently delivered and pivotal to the plot. An initially charming metaphor concerning the captive state of a ballerina figure in the child’s music box is, in the end, overused.

Abraham Lincoln famously recalled Frederick Douglass as “the most impressive man I have ever met”. He was an imposing physical figure with a mane of white hair in later life and a stentorian voice. Although The Cambria is set when Douglass was still a young man, O’Kelly should have visibly swelled and bellowed as Douglass after his identity on board was revealed and to herald the statesman who was emerging. Instead, although he plays Douglass as a calm, dignified and enigmatic presence, there is little impressive about the figure on stage. Even more sadly, there is little that is memorable from the snatches of Douglass’ speeches which were quoted – a splendid opportunity missed.

Christina Hunt Mahony, who directed the Center for Irish Studies at the Catholic University of America, now lectures in Trinity College. She is the editor of 'Out of History: Essays on the Writings of Sebastian Barry'.