Henrietta Vansittart began working on her screw propeller design. This may have stemmed from discussions and observations of naval technology related to her husband's work, but details on exactly when and how she started are not readily available.

Henrietta applied for a patent for her screw propeller, which she called the Lowe-Vansittart propeller. She was granted the patent, and later, the British Navy purchased a set of the propellers.

Henrietta Vansittart was granted a British patent for her Lowe-Vansittart propeller design, marking a significant achievement for a woman inventor in the Victorian era. This solidified her place in engineering history.

Henrietta dedicated herself to promoting and selling her propeller design to the Royal Navy and other potential customers. This period involved demonstrating the propeller's capabilities and navigating the male-dominated world of naval engineering.