How environmently unfriendly coal burners sailed into sunset
ALTHOUGH it happened over a long time, the switch from sail to steam was a most significant step in marine propulsion. Rather than relying on wind and currents, the steamers could set more direct courses, shortening their time between ports.
On a passage from Cape Town to Durban in 1946, the four-masted South African barque Lawhill took 26 days as she had to seek the westerly wind belt deep in the Southern Ocean and then she approached Durban from the south-east, running before the trade winds. A fast containership can do the Cape Town-Durban trip within 36 hours.
Because they could manoeuvre away from a lee shore more easily, steamers were less vulnerable to being driven ashore by wind or heavy seas than sailingships.
Despite this, many were wrecked in bad weather, as they were often under-powered or lost steam at a crucial time.
Caught in Table Bay during the Great Gale on May 17, 1865, the mail steamer Athens tried to put to sea, only to have a huge sea swamp the vessel, putting the fires out.
Without power, she was driven onto Mouille Point’s rocky shore.
She was lost with all hands. Despite the battering of high seas during 153 winters since that tragedy, her engine-top remains visible.
Although these early steamships offered distinct advantages, their coal bunkers took space and deadweight that could have been used for more cargo or passenger accommodation.
They were generally more prone to fire because of the furnace while coal sometimes caught fire spontaneously in the bunkers.
Paging through a South African railways and harbours magazine from the 1930s, I found an interesting article about the Cape Town harbour tug Ludwig Wiener. Fires in cargo holds or in ships’ coal bunkers, the article noted, sent the tug and indeed her consorts hurrying to sea on several occasions.
In addition, she was called to extinguish fires aboard ships in port where her powerful pumps simply flooded burning coal in the holds or in the bunkers.
While I was holding forth about coal-fired ships during our module on marine propulsion at the Lawhill Maritime Centre at Simon’s Town School, a lad put up his hand.
“Were you alive,” he enquired politely, “when these coal-fired ships were in service?” I was flattered by the question since the last coal-fired local coaster was the 1935-vintage Gamtoos, used for guano collection until she was laid up in 1971.
I&J had numerous coal-fired trawlers and the occasional coal-burning freighter passed through.
The last coal-fired tug operating in Cape Town, RB Waterston, was withdrawn only 37 years ago and I was very much alive then.
To dump the ash from their furnaces, the tugs went into the bay where for about an hour, they would drift while an ejector cleared the ash from below the furnace grating.
Before the construction of the coaling appliance adjacent to the Robinson Drydock, tugs and trawlers would be bunkered by teams of lads who would queue to have a wicker basket filled with coal.
Then hoisting the baskets upon their shoulders, they would trudge up the narrow gangway to tip the cobbles into the bunker, a process that took hours.
The new coaling appliance took less time. At least two trawlers capsized during coaling when engineroom staff forgot to close the ash-ejector valve after dumping the ash.
As the draft increased with the intake of coal, the ash ejector outlet became submerged, water rushed in, and over she went.
Pioneered in the early 1900s probably by the Shell tanker Vulcanus, internal combustion engines made rapid inroads into marine propulsion, while some larger ships had steam turbines, their furnaces fuelled by oil.
Ultimately, the cumbersome and environmentally unfriendly coal-burners sailed into the sunset.