Go back to article: Engineering and the family in business: Blanche Coules Thornycroft, naval architecture and engineering design

The hidden daughter?

The Daily Post in January 1916 reported that Blanche ‘invented CMBs’ and she replied in trenchant fashion.

Miss Thornycroft writes as follows:
…This is quite incorrect. For some years before the war my father and brother developed a special form of hull, which would not only skim on the surface of the water when driven at high speed, but also had good sea¬going qualities. Having assisted in model ex¬periments for these boats, in 1915, when my father and brothers were unable to give sufficient time to it –I merely had charge of some further model experiments which they designed and supervised.[12]

This appears to the authors to be a modest summation of her contribution based on the archival evidence available. It is possible that it may indicate an example (as described by Cathleen Folker) of a daughter ‘…finding her identity through this care of their father and his business’. It might not be too presumptuous to suggest with Folker (2008, p 157), Gillis-Donovan and Maynihan-Bradt (1990, p 153) that Blanche was one of those women in a family company, who though they ‘…may not hold a formal role and tend to be invisible’, they often wield ‘unacknowledged power and influence in the family business’.[13] Blanche also seems here to be giving credence to Rodríguez-Modroño et al’s argument that women tended to hide their important roles in the family firm (Rodríguez-Modroño, Lina Gálvez-Muñoz and Astrid Agenjo-Calderón, 2015, p 2).

Figure 12

A letter from John to Blanche Thorneycroft in response to her enquiry as to the fate of boat crewmen

A letter from John E Thornycroft – who, since 1906, had been Managing Director of the family firm – to Blanche, presumably in response to her enquiry as to the fate of the CMB crewmen involved in the Zeebrugge and Ostend raids earlier in 1918

The letter from John E Thornycroft[14] pictured here, together with its enclosures is a response to a letter from Blanche, which has not survived. From the reply it can be deduced that Blanche asked which men were involved in the Zeebrugge and Ostend raids (April/May, 1918), and who survived. She seems to have been a naval architect who cared about the men who used the craft she had worked on.

Blanche also worked on the testing of the destroyers that might, in the hands of enemy countries, be used to combat the torpedo boats. HMS Hardy was built for the British Navy and completed by the Thornycroft Company in 1913, with Blanche working on the testing of the hull design, the features of which were common to the five Acasta Class Destroyers built by Thornycroft.

Figure 13

A notebook with records of the testing of boat hull design

Blanche’s rough note book for 1912, which records the testing of the hull design for the Acasta Class Destroyers, in this case HMS Hardy

The Thornycroft Archive also contains a letter written by Blanche on 24 January 1916, which demonstrates her understanding of naval architecture as communicated to her brother John Edward Thornycroft. Her work consisted of drawing new curves to supplement earlier calculations under three different operating conditions – a wider stern, increased displacement and different centre of gravity.

Figure 14

A Letter from Blanche to John Thorneycroft

A letter from Blanche C Thornycroft to her brother John, which demonstrates her work and her caring personality

Figure 15

A monogram made of the letters T and B

Blanche signed all her work with this monogram. This example is from the cover of one of her note books but it is also used to sign the letter in Figure 14

Component DOI: http://dx.doi.org/10.15180/1851009/005