John I. Jacobs belonged to a Jewish family from Swansea and moved to London in 1880 to build up a sailing ship fleet managed from his office at 6, Billiter Street. Strong links were retained with Swansea however, with all of his sailing barques and early tankers registered there, and all flying the Star of David on their houseflag. A trade with Argentina was one of the regular routes served by his sailing ships. A dozen barques were owned during the 25-year period from 1880 to 1905 when the first steamers were purchased for conversion into tankers. The two largest barques were Magwen and Rollo, the latter built on the Clyde in 1876 and owned for twenty years from 1890 until sold as the last owned sailing ship in 1910. Swansea Castle and her sister Windsor Castle built in 1874/75 were two more of his sailing ship fleet. One old steamer was purchased from the National Steam Shipping Co. Ltd. as Greece in 1895, having been built by Palmers at Jarrow in 1863 as Virginia but she was quickly sold for scrap within a year.

The management company was converted to one of limited liability in 1905, the year in which two old tramps were purchased for carrying molasses in bulk mostly from Cuba. They were both Tyne-built, Oakwood coming from the Northumberland yard at Howdon in 1903 and purchased from the Lingham Timber & Trading Co. Ltd. of London. The other was much older, having been built as Restitution in 1885 at the Neptune yard of Wigham Richardson Ltd. and was purchased from R. Conaway & Company, Liverpool. An expansion of the molasses fleet took place in early 1911 when four tankers were purchased from the European Petroleum Company of London as Batoum, Baku Standard, Broadmayne and Vedra. The old Restitution was sold on that year to the Southern Sealing & Whaling Co. Ltd. (G.D. Irvin & C.O. Johnston), North Shields for the carriage of Antarctic whale oil, and she later foundered in 1916 on her way south from Liverpool to the whaling grounds.

Two new tanker companies were registered, Associated Oil Carriers Ltd. and Oil & Molasses Tankers Ltd., the latter to own Weehawken of 1891 purchased on 6th April 1911 from the Anglo-American Oil Co. Ltd. Another two tramps were converted into tankers in 1912, these were the Laing-built lndradeo completed in August 1902 and purchased as Falls of Momess and renamed Teakwood after conversion; and Saint Dunstan built by Swan, Hunter & Wigham Richardson Ltd. in 1900 for Saint Line Ltd. (Rankin, Gilmour & Co. Ltd., Liverpool) and renamed Beechwood after conversion. The company office was now at 10, Mark Lane, London EC. Their fleet of eight tankers was heavily occupied with carrying molasses cargoes, but the coming war was to see them carry fuel oil and gasoline, with half of them lost to German U-boats:-

11.8.1915 Oakwood

Captured/sunk by gunfire 45 miles SSE from Old Head of Kinsale o.v. Liverpool to Cienfuegos in ballast.

28.4.1917 Teakwood

Torpedoed/sunk in the Mediterranean o.v. Messina to Port Said in ballast.

19.6.1917 Batoum

Torpedoed/sunk 6m S of the Fastnet o.v. New Orleans to Queenstown with oil, 1 lost.

11.2.1918 Baku Standard

Torpedoed/sunk 6m S of Stonehaven o.v. Greenock to the Firth of Forth with fuel oil, 24 lost.

Batoum and Baku Standard had been attacked by U-boats on earlier occasions but had escaped by increasing speed. The dry-cargo tramp Tiverton was purchased during the war from Steel, Young & Company of London, and was converted into a tanker in 1920. Three dry-cargo tramps were managed during the war for the Page Shipping Co. Ltd. of 71, James Street, Cardiff as Corinth, Mary Baird and Carmelite. The latter had been built on the Wear in 1892 as Clan Macrae for Clan Line, but unfortunately this trio all became war losses. Vedra stranded on Walney Island on 7th December 1914 and burnt out while about to enter Barrow docks with benzine (petrol) from Sabine in Texas. The Cumbrian steel town was a major importer of oil from 1888 to 1926 when oil imports were relocated to river berths in the Mersey, a similar fate being suffered by the oil jetty and refinery at nearby Heysham, which was in full use from the late 1930s until 1967.

Broadmayne of 1893 was wrecked off Dartmouth on 2nd January 1921 while on a voyage from London to Newport News in ballast and attempting to drop off the Channel pilot. The fleet in the summer of 1921 consisted of three tankers, Beechwood of 1900, Tiverton of 1906 and Weehawken of 1891. A fourth tanker was purchased in 1924 as Wabasha for Oil & Molasses Tankers Ltd., having been built at Hartlepool in June 1903 as the tanker Beaumont for Fumess, Withy & Co. Ltd. and named after the town in Texas when the Spindletop oil gusher had been found in January 1901. She had been sold to the Anglo-American Oil Co. Ltd. in 1904 and renamed Seminole, but was only traded by Jacobs for two years before being sold on to German owners and renamed Nordsee and was broken up in 1932 during the Depression.

The tanker fleet was boosted in 1927 by the delivery of the first purpose-built tanker Teakwood (2) of 9,500 dwt from the Armstrong yard on the Tyne. Two larger twin-screw motor tankers were then completed in 1929/30 as Laurelwood of 11,250 dwt from the Armstrong yard and the Longwood of greater length and 14,230 dwt from the Laing yard on the Wear. The American engines-aft bridge amidships tanker Hera built in 1912 at Greenock was purchased in 1927 and retained her name, having been built for the Deutsche-Amerika Petroleum Ges. and ceded in 1919 to the U.S.A. as war reparations and she joined the Standard Oil fleet. The fleet of six tankers at the beginning of the Depression were split equally between the two companies, Oil & Molasses Tankers Ltd. and Molasses & General Transport Co. Ltd., the latter company set up in 1924. Some of the fleet were used on the bulk petrol trade to Cape Town, but Hera was laid-up at Dartmouth on 1st September 1930 until sold for scrap in June 1937 and others of the fleet had to be withdrawn from service. The old converted tankers Beechwood and Tiverton had been laid-up for years on the Tyne and were sent for scrap, Beechwood being broken up at Rosyth in February 1934 while Tiverton was dismantled at Gateshed in early 1934. A replacement was found in the new Norwegian tanker Stegg built by Laing in 1931 and renamed Rosewood in 1934.