Would the peasant railgun be possible in GURPS?

[Anders]

Here's the peasant railgun:

• Hire a ton of peasants; let's just say that it is two thousand two hundred and eighty. Line them up in single file; this will form a chain of peasants two miles long. It'd have been four miles back in MY day (witness me hiking up my 2nd Edition suspenders).
• Buy a ladder. Just buy a standard, ten-foot ladder. Disassemble the ladder into a bunch of rungs and a pair of mighty ten-foot wooden poles. Hand a pole to the peasant at the back of line.
• First round of combat. Peasant at the front of line readies an action to throw the pole at the enemy. Every peasant behind him readies an action to hand the pole to the peasant in front of him.
• Next round: peasants fire off their readied actions, passing the pole two miles down the line and hurling it in six seconds or less. Pole accelerates to the speed of 1188 miles per hour, or Mach 1.546875 in dry air, at 20°C/68°F, at sea level on our planet.
• Peasant Railgun can be reloaded and fired in less than 12 seconds.
• Variations - Really, your choice. Weapon is scalable, you could use your peasant railgun to fire a number of things at a really long range. Add more peasants to make the weapons even faster; paint them red to make them fasta. Use gobbos to make a DnD grot cannon. Hurl pointy bombs for HEAT weapons. Severed heads make an impressive psychological warfare tool. It's even more wild with a bag of holding - place a team of fighters in it for DYNAMIC ENTRY over castle walls and hell, hurl some bear cavalry directly into enemy lines, who knows. You can also throw a halfling monk to take full advantage of Flurry of Blows at 1200 mph and if you go with the falling object rule for 5e with the wooden rod being 7 lbs you have 5-9 lb per 60 ft do 2d6, making the rod going about 2 miles per 6 seconds making it do 300d6 A TURN!!!! Combine this with the 15,000,000 gold-a-day trick and you're ready to absolutely ruin your DM's day.
• ????
• PROFIT

How quickly would the projectile travel? GURPS has 1-second rounds, so I guess it would go six times faster, right? How much damage would it do?