Checking an explicitly specified spring grid

For a hypothetical planning exercise, a rectangular opening measures 36 cm by 36 cm. Each selected spring occupies an 8 cm diameter envelope, and the exercise requires 2 cm clear space between neighbouring envelopes plus 2 cm at each outer boundary. The trainee draws a 3 by 3 grid and asks whether it fits, then suggests that a 4 by 4 grid might provide more support. These are supplied geometry assumptions for a classroom estimate, not universal trade clearances or authorization to install the springs on a real object. The supervisor asks for a complete width calculation, including both inner gaps and both boundary spaces. No compression fraction, fastener length or actual load rating has been supplied. A real assembly would still need the appropriate design and practical assessment.