Considering the crowd size, I must have been amongst the few unacquainted with this motor sport. If you’ve not encountered it, read on for a brief description.

The pictures show vehicles, familiar and strange, engaged in a contrived show of force. They attempt to drag a fiendishly devised, weighted trailer along a 100m dirt-track course. The further the trailer travels, the more its weight 'bites' and so progressively more force is required to delay the inevitable shuddering halt.

The trailer weight is tuned to the pulling power of different classes of competitor. Classes range from basic agricultural tractors with specially tuned engines through to custom-built rigs employing multiple aero-engines.

I am not an aficionado, I just happened on an event attached to a local agricultural show. It is an extraordinary spectacle to see (and hear!) such monster hall a huge dead weight at speeds up to 30 mph. I understand the pastime originated in North America.

Learn more from the British horse's mouth: http://www.tractorpulling.co.uk