Calc Mortal Engines - London crawling

Mortal Engines is a world where cities wander around and eat each other for reference. First up is an easy one; Salthooks speed.

Mortal Engines said:

"The town is called Salthook," boomed the voice of the announcer. "A mining platform of nine hundred inhabitants. She is currently moving at eighty miles per hour, heading due east, but the Guild of Navigators predicts London will catch her before sundown. There are sure to be many more towns awaiting us beyond the land bridge; clear proof of just how wise our beloved Lord Mayor was when he decided to bring London east again..."

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80m/h is equal to 128.7km/h, or 35.75m/s. And London is even faster than this. Now onto it's energy.

Mortal Englines said:

"The town is called Salthook," boomed the voice of the announcer. "A mining platform of nine hundred inhabitants. She is currently moving at eighty miles per hour, heading due east, but the Guild of Navigators predicts London will catch her before sundown. There are sure to be many more towns awaiting us beyond the land bridge; clear proof of just how wise our beloved Lord Mayor was when he decided to bring London east again..."

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The speed is 80 miles an hour (35.7632m/s), and has a height of 2000 feet (609.6m). Now onto Londons engine power and the kinetic energy generated.

The mining town saw the ganger and turned tail, but already the huge caterpillar tracks under London were starting to roll faster and faster. Soon the city was lumbering in pursuit, a moving mountain of metal that rose in seven tiers like the layers of a wedding cake, the lower levels wreathed in engine smoke, the villas of the rich gleaming white on the higher decks, and above it all the cross on top of St. Paul's Cathedral glinting gold, two thousand feed above the ruined earth.

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London has a height of 2000 feet (609.6m), and keep in mind that traction citites are generally wider than they are tall. The longest ship in the world to date is the Seawise Giant, which is 458.46m long (so London is taller and wider than the biggest ship in the world, and likely weighs a lot more too). It's a good place to start though. The Seawise Giant weighs 657,019 tons, or 657,019,000kg. Putting that through the kinetic energy calculator gets a result of 420165777349.3452 joules, or 100.42203091523546732 tons of TNT. For reference, put into a bomb that's enough energy to level multiple city blocks. Or a lot. And as said above, I feel the final result would ultimately be even higher than this. And then there are the tracks it created in the ground, which confirm this level of power.

A Darkling Plain said:

London's wake ran ruler straight toward the east. Each of the city's tracks had plowed a trench two hundred feet wide and often almost as deep. Tom steered the Jenny along the northernmost one until the ribbon of sky above him started to turn pale. Then he set her down to wait out the hours of daylight.

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Final Results
Salthook flees London = 35.75m/s
London's kinetic energy = >100.422 tons of TNT

Please keep in mind that for energy the above is a ludecrous low end.