This thread was originally written and published in May 2019. It has been lightly edited and corrected as applicable for this post.
I’m quoting myself here as after a little bit of searching, Mr Morton’s Patent Slip is quite the fascinating thing.
The Patent Slip – or “marine railway” – was basically 3 rails on an inclined plane, up which a ship could be hauled by winch supported by a special wagon.
The patent slip cost about 1/10 of the equivalent dry dock, and was simpler and more efficient to operate.
Here is a painting of the Burnham patent slip, by Fitz Henry Lane, 1857.
The patentee, Mr. Morton – Thomas Morton (1781 – 1832) – was a native of Leith, invented his slip in 1818 and patented it in 1819. I believe it was 1821 or 1822 when he built his first with his own money (in Bo’Ness), and at some point soon after one appeared in Chalmer’s shipyard in Leith off Coburg Street (where the car park now is)
Now, that last map was Kirkwood’s plan of 1817, so that predated the patenting of the slip by 2 years, so there must have been a dry-dock (or conventional launching slip) there that was replaced by the patent slip and there is nothing on the 1807 plan at all.
And here it is on Charles Thomson’s map of 1822. Notice also the dry docks on the south bank of the river and at Ronaldson’s Wharf (above the word “Harbour” on the map).
The shipyard was not that old at the time, it appears around the turn of the 19th century, I think on land reclaimed when Cob[o]urg Street was built up and formalised at the current level.
In 1844, the railway was driven through to North Leith aka Leith Citadel station beyond and a coal yard took the place of the shipyard on the river bank. I suspect that the slip was really too far up the river to be that attractive to all but the smallest vessels.
The rapidly expanding Leith Docks also built much larger new stone graving docks at great expense, which would have been more accessible and attractive to modern shipping.
A mile or so along the coast at Granton though, an altogether grander Patent Slip was constructed at the David Allan & Co. shipbuilding yard (that had re-located there from Leith) , it is shown below on the 1876 map, but it is also on the 1849 map.
The Granton patent slip was not only much bigger, but was also powered by its own engine house (rather than muscle-driven winch as at Leith). Notice that West Harbour Road crosses over the slip on a swing bridge!
As shipbuilding in Granton waned and concentrated on building small craft (particularly trawlers and drifters), the patent slip appears to have been replaced by a more conventional and much smaller launching slip. It disappears from maps after 1912.
Such was the success of his patented device, Morton’s representatives were in court as early as 1824 to contest an infringement of it, and won. Morton tried to extend his 10 year patent in parliament 1832 but failed, and although there was talk of compensation he died that year
The parliamentary hearing recorded that the berthing of a ship in a dry dock that would cost 170/- would cost 3/- on Morton’s slip. I assume that was 3/- of coal and manpower to haul the ship up a slip vs. 170/- to pump out a dry dock then brace the hull.
And patent slips are still in use, and still called that even though the patent ran out nearly 200 years ago! Here’s a modern incarnation in Arbroath .
The Clyde, unsurprisingly, also got patent slips, here are those of Henderson’s (L) and Inglis (R) at the mouth of the Kelvin.
This advert for Bristol shipbuilders Ross & Sage mentions some of the virtues of the patent slip, not least how quickly a vessel could be removed and returned to water, without waiting for a dry dock to be drained and flooded again .
I assume the “longer time for working during winter days” is a reference to the dependence on daylight for working, which would have been in short supply at the bottom of a dry dock.
Here is Calmac’s ferry “Loch Striven” being slowly let back down the patent slip and into the Clyde.
Notice these vessels don’t have traditional propellers, they have “cylcoidal propulsors”. Think big egg whisk. Full power can be applied in any direction making them super manoeuvrable when docking.
Back to patent slips, and the “Big Chute Marine Railway” is an extreme expression of it. It links 2 sections of the Trent-Severn waterway in Ontario instead of a traditional canal lock. Initially a temporary measure, it’s still going 100 years later.
The Monkland Canal, from Lanarkshire to Glasgow used an inclined plane railway too (at Blackhill), but the vessel being moved was kept in a caisson of water instead of on a dry frame. This was not a cost-saving measure, but a water saving one.
Here we go. The inclined plane was also found to be much quicker to transit, although speed was never particularly pressing on slow-moving canals whose primary business was moving non time-sensitive cargoes like coal.
There’s a great model of this inclined plane at the @NtlMuseumsScot on Chambers Street, but I can’t find a picture of it so you can all just go visit it if you want to see!
And here’s an original drawings held by @scottishcanals. To me this looks like the vessel would not have been in water but held dry on the frame instead, much closer to Morton’s patent than what was eventually built.
Well here we go! I found the Morton family graves in South Leith Kirk after 45 minutes methodical searching in the beautiful weather. Thomas is just legible on the panel on the left.
This perhaps help to visualise it.
The Morton family’s shipyard – S. & H. Morton & Co., S(amuel) and H(ugh) were Thomas’ uncle and father respectively – in Grangemouth was moved back to Leith in 1844 after his death. They occupied a yard on ground that would later become Henry Robb’s, Leith’s last shipyard.
An 1880 advert for Morton’s engineering company that had by this time moved from shipbuilding to specialising in supplying shipyards.
The 1851 P.O. directory lists the offices on Leith Walk and I assume the works at Granton .
Given Morton died in 1832, I assume the Thomas Morton listed at his address in 1852 was his son .
Descendents of Morton’s company, controlled by relatives, built ships at Leith and Granton up to the 1890s when they were bought over by Hawthorns & Co. engine and boiler makers also of Leith. There’s a Hawthorns-built steam locomotive in the NMS on Chambers Street also .
Hawthorns of Leith were a subsidiary of Hawthorns of Newcastle-upon-Tyne, who later became part of Hawthorn Leslie & Co. which will ring a bell to anyone with an interest in ships or shipbuilding
Coincidentally, the Hawthorns yard in Leith was opposite Hugh Morton’s original yard (at Couper Street), where the State Cinema currently was .
Hawthorn’s yard was bought in 1924 by one aspiring young shipbuilder, Henry Robb, who would become the biggest and the last name in Leith shipbuilding – on a site that had once been the Morton’s yard.
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[…] That ship may even be on a “patent slip”, a Leith invention. […]