The total energy in the beams is the particle energy in GeV (normally called the beam energy) multiplied by the number of particles. at 7TeV this equates to the kinetic energy stored in an aircraft carrier at 12 knots. Relativity does not apply to things whose speed is measured in knots, they were excused.
So, half the beam energy of 3.5TeV, assuming the same luminosity = number of protons, results in the aircraft carrier moving at root2 x 12 knots.
In full running condition, dozens of individual beams are packed into a square lattice within the beam cross-section, Im not sure how many of these they are running right now. This aspect of the machine is incredibly clever - how they cool down the transverse momentum of the protons so that they stay in tight 0.5mm beams for 100 hours. This looks to be working, as the screenshot suggests - and is worthy of another Reg article.
Keep up the good work.