Upgrade - Drill Speed

>>in-game description:
>>Increases the number of times the drill spins per second.

It makes your drilling faster.

Drill Speed Mk-3
Wire Rope Compression Spings Spiral Bevel Gear Internal Combustion Engine	1 1 1 1

Default	Base drill speed
Mk-1	+10% drill speed
Mk-2	+30% drill speed
@Mk-3	+40% drill speed
Mk-4	+60% drill speed
Mk-5	+70% drill speed
Mk-6	+80% drill speed
Mk-7	+90% drill speed
Mk-8	+100% drill speed

*This data is taken from descriptions in Engneering Bay.