Why was eniac so heavy?

Answer 1

ENIAC, the Electronic Numerical Integrator and Computer, was heavy primarily due to its use of vacuum tubes for computation, which required substantial power and support infrastructure. It also featured large banks of electrical components, including resistors, capacitors, and extensive wiring, all housed in a robust frame for stability. The machine's size and weight were further amplified by its need for cooling systems and power supplies, essential for maintaining its operation. Overall, its design prioritized functionality over portability, resulting in a massive and heavy structure.