The figures were also up because of increases in the rental rates, which is down to a $22m spend in new heavy cranes over the past 12 months, which have higher utilisation and rental income than smaller, older cranes, said Hyde Park Acquisition Corp, which announced in March the intention to buy the company for $210m.

For the quarter ended March 31, 2008, the total number of actual crane rental days equaled 71.8% of the total available days versus 68.1% for the comparable quarter in 2007. The average monthly rental revenue rate increased 27.2% to $19,163 for the three months ended March 2008 from $15,068 for the three months ended March 2007.

Equipment rental revenue backlog increased by 28.7% to $43.1 million at March 31, 2008 from $33.5 million at December 31, 2007. Essex management said this reflects continuing strength in infrastructure-related end-markets. Management estimates that based on the Company’s actual equipment rental revenues and Essex’s backlog as of March 31, 2008, approximately 90% of projected 2008 equipment rental revenue has been booked.

Essex Crane Rental Corp is based in Chicago, and has more than 350 cranes and attachments in its fleet. Essex supplies cranes for construction projects related to power generation, petro-chemical, refineries, water treatment & purification, bridges, highways, hospitals, shipbuilding, and commercial construction.

Hyde Park Acquisition Corp. was incorporated in Delaware on August 21, 2006 as a blank check company whose objective is to effect a merger, capital stock exchange, asset acquisition or other similar business combination with an operating business. Hyde Park’s initial public offering was declared effective March 5, 2007 and was consummated on March 13, 2007, resulting in net proceeds of $100m through selling 13m shares at $8 each. Each unit was comprised of one share of Hyde Park common stock and one warrant with an exercise price of $5.00. As of May 31, 2008, Hyde Park held $101.9 million in a trust account maintained by an independent trustee, which will be released upon the consummation of the business combination or the liquidation of Hyde Park.