Robert Pendrill Thomas – Mercantile Marine - S.S. Bayronto

Third Engineer Robert Pendrill Thomas – Mercantile Marine, S.S. Bayronto

Early Life and Family Background

Robert Pendrill Thomas was born in 1888 in Morriston, the youngest son of Robert Thomas and Hannah Davies.

1891 Census

At the time of the 1891 Census, the Thomas family lived at 205 Plas y Coed, Morriston. Robert senior, aged 43, worked at the steelworks, while Hannah, aged 42, managed the home. Their children were Margaret (18), a Stocking Maker; Alice Jane (15); Mary (12); Hannah (9); Joseph D. (7); Charlotte (4); and Robert T., then just 3 years old.

1901 Census

By the 1901 Census, the family had moved to 10 Railway Terrace, Cilybebyll. Robert, now 52, was employed as a Rollerman, and Hannah was 51. Present at home were Hannah (19), a Dressmaker; Joseph D. (17), working in the steelworks; Charlotte (14); and Robert T., aged 13.

1911 Census

The 1911 Census records him as Pendrill Thomas, residing at Plasy Coed, Roath Lake E, Llanishen, the home of his brother-in-law, David Evans, a 37-year-old University Professor of Mines, and his wife Mary (32). Their children were Robert Arthur (10), M. D. Arwyn (5), and Ernest Hywel (3). Also present were Lottie Thomas (24), a Music Student, and Pendrill Thomas (23), employed as a Fitter, both siblings of Mary. A servant, Alice Hughes (26), was also in the household.

Service at Sea – Third Engineer, S.S. Bayronto

As an experienced engineer, Robert Pendrill Thomas later served as Third Engineer aboard the S.S. Bayronto, a British merchant steamer involved in wartime trade during the First World War. His role in the engine room required technical skill, precision, and constant vigilance, ensuring the ship’s boilers and machinery functioned safely under wartime conditions.

S.S. Bayronto

The S.S. Bayronto, a British steam cargo ship, operated on transatlantic and coastal routes, transporting vital wartime supplies. On 30^th July 1918, while sailing near the American coastline, the Bayronto came under attack from the German submarine UB-88. Although the vessel survived the torpedo strike and remained afloat, the explosion caused significant internal damage.

Robert Pendrill Thomas was the only casualty, killed during the attack. The Bayronto managed to reach port but later foundered in 1919 due to structural weaknesses caused by wartime damage.

German Submarine UB-88

The UB-88 was a Type UB III submarine of the Imperial German Navy, launched in 1917. Designed for long-range patrols, she carried ten torpedoes and was armed with a deck gun, making her one of Germany’s most powerful coastal U-boat hunters of the late war period. Operating primarily in the Atlantic, UB-88 targeted merchant shipping as part of Germany’s effort to disrupt Allied supply lines.

After the war, UB-88 was surrendered to the United States in 1918 and later used for naval inspection and explosive testing before being scuttled off the Californian coast.

Commemoration

S.S. Bayronto
Tower Hill Memorial, London
credit - Benjidog Historical Research Resources:
The Merchant Navy Memorial 

Robert Pendrill Thomas
St. Samlet Church
credit - CWGC

Although Robert Pendrill Thomas has no known grave at sea, his body was recovered and returned home to Swansea. He is buried at St. Samlet Churchyard, Llansamlet, making him the only First World War Mercantile Mariner from Swansea to be laid to rest locally. His name is also commemorated on the Tower Hill Memorial, alongside thousands of fellow mariners who died with no known grave.

Legacy

The loss of Third Engineer Robert Pendrill Thomas highlights the dangerous and often overlooked service of the Mercantile Marine. His death as the sole casualty of the Bayronto’s torpedo attack reflects the constant risks faced by engineers who worked deep below deck, far from the possibility of escape during submarine assaults. His sacrifice is remembered as part of Swansea’s maritime heritage and the wider contribution of merchant seafarers to Britain’s survival during the First World War.