SH Archive 1868: Bermuda Floating Dry Dock

[KD Archive]

I think we have a fairly decent ship collection already, but the gifts just keep on coming. This time we have a floating dock. One of the more attractive aspects of the Victorian Age was the willingness to take on large and often unprecedented engineering challenges. I will just quote from some sources here.

1868 Floating Dry Dock​

By the 1860s the floating dock concept was known and proven but the growth in ship size demanded that what was needed for Bermuda would be the biggest such unit yet built. It was to take ships of up to 10000 tons – including Britain’s new ironclads – but its location in Bermudan waters, where marine growth was likely to foul it underwater valves and piping, would demand the facility to allow regular “careening” – cleaning by scraping. The design that resulted was 380 feet long and 120 feet separation between its vertical sides. It could accommodate vessels longer than its own length and its own displacement was 8400 tons.

​

Construction started at the Campbell and Johnstone shipyard on the river Thames, near Woolwich, in 1866 – in this period, and up to the beginning of the 20th Century, London was still a major ship-building centre. Construction was of iron – regular use of steel was still a decade or more in the future – and some 1400 men were involved in the work. It was launched, after one failed attempt, in September 1868 and was taken downriver to Sheerness, where it was submerged to wait out winter storms until the following year.

​

Sequential operation of floating drydock as illustrated in an 1870 book on the Bermuda project. A ship could then be manoeuvred between the sides and when the bottom compartments were once more pumped dry the dock would rise, carrying the ship with it. An additional advantage of such docks is that they are mobile and can be built at a shipyard and towed thereafter to another location, or even succession of locations.

After its successful arrival in Bermuda the floating drydock was to provide over three decades of service until replaced by a new, steel, unit, in 1906.

Cruiser HMS Psyche in the floating dock, c. 1900

It was sold for scrap thereafter to a German company but while being towed away broke loosed and grounded on a reef. Her remains are still visible off Spanish Point, Bermuda.

Bermuda Floating Dock, From Spanish Point

​

Sources and Links:

• Bermuda’s Floating Dry Dock 1869 + 1​
• Royal Naval Dockyard, Bermuda - Wikipedia​
• Floating Dock Bermuda​

​

KD: So, there it is then. 1868-69. And here comes my favorite part:

• One of the more attractive aspects of the Victorian Age was the willingness to take on large and often unprecedented engineering challenges.​

Note: This OP was recovered from the Sh.org archive.

Note: Archived Sh.org replies to this OP are included in this thread.

 

[Timeshifter]

Note: This post was recovered from the Sh.org archive.
Username: Timeshifter
Date: 2019-12-08 07:30:29
Reaction Score: 1

Not bad, whilst scooting about with Horse and cart tech... All the iron! The poor horses!

As always KD, it makes no actual sense.

Do we know why Bermuda?

 

[Archive]

Note: This post was recovered from the Sh.org archive.
Username: jd755
Date: 2019-12-08 17:01:01
Reaction Score: 0

From here via startpage; The arrival of the Bermuda floating dock, July 1869
Lieutenant-Colonel Andrew Clarke, Royal Engineers, director of works at the Admiralty, had chosen a floating dock for the repair of warships at Bermuda because it was impossible to operate a dry dock given the porous limestone of the local terrain. The dock was sufficient in size to accommodate the largest warships in the British fleet, had a u-shaped cross section and a self-careening ability. The latter feature meant that it could dramatically turn itself on its side for the purposes of maintenance, or the removal of marine growth. The launching took place at the Campbell, Johnstone & Co. shipyard at North Woolwich in September 1868 and the delivery voyage started from Sheerness in June 1869.

The dock was towed from Madeira across the Atlantic by the iron warships HMS Warrior (1860) and HMS Black Prince (1861), with the wooden paddle frigate HMS Terrible (1845) guiding from behind. The dock’s progress was assisted by the action of easterly winds on a sail erected between the side walls of the structure. On the approach to the naval anchorage at Ireland Island, the dock had to be carefully navigated through The Narrows, a channel between the reefs that surround Bermuda. This was undertaken by the Terrible, with the gunboats HMS Vixen (1865) and HMS Viper (1865) made fast to each quarter of the dock.

Coloured print showing the departure of the Bermuda floating dock from Porto Santo on 4 July 1869 (RMD ID: PAI8972)

Here's its replacement.
Bermuda Dock AFD 1 1902