Portsmouth Writers’ Season: Michael Underwood

For this next post in our Portsmouth Writers’ Season, we turn to the author and architect Michael Underwood and his new book Gunwharf Quays Portsmouth. Spanning almost 500 years the book (available hereexamines the history, architecture, conservation and development of a remarkable local site. Enjoy the following extracts.

Old Gunwharf (17th/18th century)

In 1699 the Board of Ordnance reported ‘the wharf where our guns lie is not in very good condition …. it might be better to have another wharf built particularly for the guns’. The 1688 “Glorious Revolution” had led to an alliance between England and Holland against attempts by France’s King Louis XIV to regain England for James. This initiated wars with France for over a hundred years. A peace treaty of 1697 was indecisive, and war broke out regularly until the battles of Trafalgar and Waterloo in the early 19th century.

These wars and threats of wars brought about further expansion of the Royal Navy with a new 1690s dockyard at Plymouth and expansions at Chatham and Portsmouth. At Portsmouth, too, there were problems of insufficient and unsuitable munitions storage.

Ad hoc arrangements such as those in Portsmouth at the end of the 17th century just would not do; planned gunwharves, carefully designed and properly constructed, became essential. These matters occupied the minds of the engineers of the Board of Ordnance in the early decades of the 18th century; the designs for their storehouses and other buildings were inspired by the muscular ‘castle-air’ architecture of John Vanbrugh and Nicholas Hawksmoor at the Office of Works and the design legacy of Sir Christopher Wren.

Initially it was thought that a new gunwharf could be built in the Camber near Pierson’s Quay. However, William Boulter, Assistant Surveyor of the Office of Ordnance, considered that it ‘must be erected on that part of the Ouze between high and low watermark that lies nearest to the mill’. A cheaper proposal by the Board for a wharf  at Blockhouse Point (on the Gosport side of the harbour) was overruled by the Admiralty.

 Reclaiming the land

Before any building work could begin, land had to be reclaimed from the mudflats for what was to become the fourth gunwharf at Portsmouth. Work was underway in 1707.

Quay walls were set out following the perimeter lines of the revised Board of Ordnance plans; the stonework being laid section by section on timber piles. Then the site area within the quay walls was progressively built up with soil and gravel excavated from areas east of the dockyard within what was known as West Docke Fields (later  known as ‘The Common’ and later still as the dock-workers’ town ‘Portsea’). The wharf was positioned between the mill-pond creek and a creek further north, maximising water depth along the sides.

By around 1714 reclamation had been completed and many of the necessary buildings erected or under construction.

The first designed gunwharf

The gunwharf at Portsmouth (built c1707-1715) was the first purpose-designed example in the country and, as a consequence, fulfilled all the requirements. It was followed by others: Chatham (c1717), and Morice Yard (1719-25) at Plymouth dockyard (later known as Devonport).


east end

East end of Old Gunwharf c.1800 showing the Officers’ houses, the Grand Storehouse  and the Main Gate (illustration ⓒ Robert Kennedy and Michael Underwood)

New Gunwharf (19th Century)

‘We must destroy the English monarchy or expect to be destroyed by these intriguing and enterprising islanders – let us concentrate on the navy’ Napoleon Bonaparte, 1797.

Events in Europe, exacerbated by Napoleon’s rise to power in the 1790s, generated a climate of fear throughout Britain and led to an expansion of her armed services and fortifications. The number of naval ships virtually doubled between 1780 and 1800. Between 1793, when the wars against France began, and the final defeat of Napoleon in 1815 government expenditure created a debt of £578 million. During the economic crisis of 1810-12, unemployment rose, food became scarce and discontent spread as the war ground on devouring the country’s resources.

The worlds largest industrial complex

At the Portsmouth dockyards, after several years of planning, the Great Basin was enlarged and dry docks added from 1799 following the plans of Sir Samuel Bentham, Inspector-General of Naval Works. He initiated the use of steam engines, machine tools (including Marc Brunel’s innovative block-making machinery) and the early use of iron in buildings and the royal dockyards at Portsmouth expanded to become the world’s largest industrial complex.

A new gunwharf

A review in 1797, under Bentham, led to the Board of Ordnance commissioning further wharf space ‘for the improvement and enlargement of the Ordnance Gunwharf’ on the ‘Ouze’ next to the existing Gunwharf and to the south of the Mill creek. Under the direction of Royal Engineer, John Evelegh, quay wall construction and infilling seems to have started immediately.

The site

The proposed wharf, ‘planned’ in accordance with eighteenth century principles, would be built out from the ‘sea line’ defensive wall and rampart (which protected and contained the town moat) over the ouze. The creek, with its important tidal mill (the King’s Mill) supplying flour to the Navy, had to be maintained. This new wharf became known as New Gunwharf, whilst the existing wharf became Old Gunwharf; the combined wharves formed Portsmouth’s fifth gun wharf – the largest in the country.


New Gunwharf and the western end of Old Gunwharf c 1860 (illustration ⓒ Robert Kennedy and Michael Underwood)

Foundations for Gunwharf Quays – 20th century

This unpromising site not only had deep layers of 18th and 19th century infill on mud and gravel beds, but also contamination from its military uses requiring remediation.

Large structures often require piled foundations rather than brick or concrete footings: in the Georgian period timber piles were used; concrete piles were used for the post-war Creasy building. In 1999 the materials were steel as well as concrete.

The southern, residential, half of Gunwharf was the most straightforward; most of the buildings were built off continuous-flight auger pile deep foundations (bored holes filled with concrete as the auger drill is withdrawn).

More difficult was the northern half where a  deep, two-level basement car-park structure, the lower floor being well below sea level, was to occupy most of the existing site. The works had to be protected from the ingress of the sea, so an enclosing water-proof ‘secant’ wall, of more than 2,000 interlocking piles, was installed before excavation of the contained ground and the sea wall was raised. A further 1,345 auger piles were bored into the excavated surface providing support for the car park structure and the commercial development above.

Site looking north

Gunwharf Quays basement car-park and secant-piled wall under construction 1999 (illustration ⓒ Myles Waterman and Michael Underwood)

BookCover - front - Version 2


Micheal Underwood’s book is available in Portsmouth’s Waterstones and Blackwells, in John Lewis and WH Smith in Southsea and online here.