Editing Steamship (section)

==Long-distance commercial steamships==
The most testing route for steam was from Britain or the [[East Coast of the United States|East Coast of the U.S.]] to the [[Far East]]. The distance from either is roughly the same, between {{convert|14000|to|15000|nmi}}, traveling down the Atlantic, around the southern tip of Africa, and across the [[Indian Ocean]].<ref name=MacGregor/> Before 1866, no steamship could carry enough coal to make this voyage and have enough space left to carry a commercial cargo.

A partial solution to this problem was adopted by the [[Peninsular and Oriental Steam Navigation Company]] (P&O), using an overland section between [[Alexandria]] and [[Suez]], with connecting steamship routes along the [[Mediterranean]] and then through the [[Red Sea]]. While this worked for passengers and some high value cargo, sail was still the only solution for virtually all trade between China and Western Europe or East Coast America. Most notable of these cargoes was [[tea]], typically carried in [[clipper]]s.<ref name="Jarvis">{{cite book |last=Jarvis|first=Adrian|editor1-first=Robert|editor1-last= Gardiner|editor2-first=Dr. Basil|editor2-last= Greenhill
|title=The Advent of Steam - The Merchant Steamship before 1900 |publisher=Conway Maritime Press Ltd |date=1993 |pages=158–159|chapter=Chapter 9: Alfred Holt and the Compound Engine |isbn=0-85177-563-2}}</ref>

Another partial solution was the Steam Auxiliary Ship – a vessel with a steam engine, but also rigged as a sailing vessel. The steam engine would only be used when conditions were unsuitable for sailing – in light or contrary winds. Some of this type (for instance [[SS Erl King (1865)|''Erl King'']]) were built with propellers that could be lifted clear of the water to reduce drag when under sail power alone. These ships struggled to be successful on the route to China, as the standing rigging required when sailing was a handicap when steaming into a head wind, most notably against the southwest monsoon when returning with a cargo of new tea.<ref name="Clark">{{cite book |last=Clark|first=Arthur H. |date= 1911|title=The Clipper Ship Era, An Epitome of Famous American and British Clipper Ships, Their Owners, Builders, Commanders, and Crews 1843-1869|publisher=G P Putnam’s Sons, New York and London, The Knickerbocker Press |pages=331–332 }}</ref>  Though the auxiliary steamers persisted in competing in far eastern trade for a few years (and it was ''Erl King'' that carried the first cargo of tea through the [[Suez Canal]]), they soon moved on to other routes.

What was needed was a big improvement in fuel efficiency. While the boilers for steam engines on land were allowed to run at high pressures, the [[Board of Trade]] (under the authority of the [[Merchant Shipping Act 1854]]) would not allow ships to exceed {{convert|20|or|25|psi}}. Compound engines were a known source of improved efficiency – but generally not used at sea due to the low pressures available. [[SS Carnatic|''Carnatic'' (1863)]], a P&O ship, had a compound engine – and achieved better efficiency than other ships of the time. Her boilers ran at {{convert|26|psi}} but relied on a substantial amount of [[Superheater|superheat]].<ref name=Jarvis/>

[[Alfred Holt]], who had entered marine engineering and ship management after an apprenticeship in railway engineering, experimented with boiler pressures of {{convert|60|psi}} in ''Cleator''. Holt was able to persuade the Board of Trade to allow these boiler pressures and, in partnership with his brother Phillip launched [[SS Agamemnon (1865)|''Agamemnon'']] in 1865. Holt had designed a particularly compact compound engine and taken great care with the hull design, producing a light, strong, easily driven hull.<ref name=Jarvis/> [[File:StateLibQld 1 133053 Agamemnon (ship).jpg|thumb|upright=1.25|SS ''Agamemnon'' (1865)|alt=]]

The efficiency of Holt's package of boiler pressure, compound engine and hull design gave a ship that could steam at 10 knots on 20 [[long tons]] of coal a day. This fuel consumption was a saving from between 23 and 14 long tons a day, compared to other contemporary steamers. Not only did less coal need to be carried to travel a given distance, but fewer firemen were needed to fuel the boilers, so crew costs and their accommodation space were reduced. ''Agamemnon'' was able to sail from London to China with a coaling stop at [[Mauritius]] on the outward and return journey, with a time on passage substantially less than the competing sailing vessels. Holt had already ordered two sister ships to ''Agamemnon'' by the time she had returned from her first trip to China in 1866, operating these ships in the newly formed [[Blue Funnel Line]]. His competitors rapidly copied his ideas for their own new ships.<ref name=Jarvis/>

The opening of the [[Suez Canal]] in 1869 gave a distance saving of about {{convert|3250|nmi}} on the route from China to London.{{efn|The distance by a modern shipping route calculator is {{convert|13373|nmi|km mi}} from London to Fuzhou via the Cape of Good Hope. Using the same calculator, a route through the Mediterranean and Suez Canal is {{convert|10124|nmi|km mi}}. The difference is {{convert|3249|nmi|km mi}}. A sailing vessel would take a longer route to obtain the best winds, so this comparison is only an approximation.<ref>{{cite web |last1=systems |first1=maritime data |title=London - Fuzhou distance is 10120 NM - SeaRoutes |url=https://classic.searoutes.com/routing/4294967421/(51.460079193115234,%200.35891589522361755)/4294968183/4294968021?speed=10&panama=true&suez=true&kiel=true&rivers=block&roads=block&avoided-ports=GBLGP |website=m.classic.searoutes.com |access-date=23 October 2021 |language=en}}</ref>}}  The canal was not a practical option for sailing vessels, as using a [[tug]] was difficult and expensive – so this distance saving was not available to them.<ref name=Jarvis/> Steamships immediately made use of this new waterway and found themselves in high demand in China for the start of the 1870 tea season. The steamships were able to obtain a much higher rate of [[Freight rate|freight]] than sailing ships and the insurance premium for the cargo was less. So successful were the steamers using the Suez Canal that, in 1871, 45 were built in Clyde shipyards alone for Far Eastern trade.<ref name="MacGregor">{{cite book |last=MacGregor |first=David R. |date= 1983|title=The Tea Clippers, Their History and Development 1833-1875 |publisher=Conway Maritime Press Limited |isbn=0-85177-256-0}}</ref>