GREMLIN
The Magnetic Spatula Resonance Field Knox Launcher, or GREMLIN (as designated by the US Dept of the Navy).  The GREMLIN is capable of hurling large sections of decommissioned Knox-class guided missile frigates upon its targets.  It uses the magnetic resonance field of a specially designed spatula to propel the sections of hull through the launch tube.

It is the size of a large water tower.  It is located North of Washington D.C.  Each round weighs about 1000 tons.  Range is 100miles, rate of fire is 1 round every 15 min.  Accuracy of operators is a 13.
Link to Knox Class Frigate

The Gauss Spatula Launcher
If that isn't enough to stop the Panzers, or if we're feeling especially sadistic, there is another weapon which you may find of interest.  The Gauss Spatula Launcher works along the same premise as a railgun.  It uses magnetic coils to accelerate a projectile (in this case, a spatula) up to speeds well above that of sound waves.  The spatula has several powerful effects.  The first is that it will punch a hole through even the thickest of modern armor.  Second, the force of the kinetic impact will send a shockwave throughout the target, severely crippling its integrity if not outright destroying it.  Third, the special layer of Boy Scout dining hall scrambled egg-substitute that each projectile is coated with will, after being heated by its atmospheric flight, consume and decompose any and all matter organic or otherwise that it comes in contact with.

The GSL is mounted on the back of an old Blue Dodge Ram Pickup Truck.  The GSL can penetrate the frontal slope armor of a M1A2 tank.  Range is 1 mile and Rate of Fire is 4 per minute.