Technically they throw it up in the air but I'll just calc the LS for this.
224 px = 154.94 cm (same height as his IDW counterpart, since this game is inspired by the IDW comics and incarnations)
824 px = 569.957857 cm, radius 284.978928 cm
24 px = 16.6007143 cm
Using a cylinder and ignoring some of the extra bits of the lid...
4235475.2179038 cubic cm x 6800 kg/m3 (density of cast iron, what sewer lids are made of) = 28801.2315 kilograms / 4 (for each turtle) = 7200.30788 kg (Class 10)
Toss & Force[]
Decided to calculate the throw after posting it, it feels a bit empty without it
Top handle thingy: 170 px
Bottom handle thingy: 135 px
Relative to the lid, this handle thingy is 160.951554 cm
Angisizing formula: object size * panel height in pixels/[object height in pixels*2*tan(70deg/2)]
For top handle: 160.951554 x 782/[170 x 2 x tan(70deg/2)] = 528.684074
For bottom handle: 160.951554 x 782/[135 x 2 x tan(70deg/2)] = 665.750316
665.750316 - 528.684074 = 137.066242 cm
It traveled this much in 1 frame of a 60 fps video or 0.0166666667 seconds
137.066242 cm per 0.0166666667 seconds = 82.239745 m/s
Now acceleration
And force
142105276.221 N = 14490705.411 kgf (Class M)
So "At least Class 10, likely Class M"
KE[]
And since it's a throw, KE can be counted for this
97396774.018938 J = 23.27838767183 kg of TNT, divided for each turtle that's 24349193.5 J or 5.81959692 kg of TNT (Small Building level)