Depth of Engine Foundation ($D_f$):

$$D_f = \frac{V_f}{w_e + L_e}$$

Where:

• $D_f$ is the depth of the foundation, m.
• $V_f$ is the volume of the foundation, m³.
• $w_e$ is the width of the engine plus allowance, m.
• $L_e$ is the length of the engine plus allowance, m.