Overall, a Heavy Cannon (1 on 1) would have a good chance to beat a Great Bombard with full health, though it would rely on the Heavy Cannon getting two shots off (12 seconds) before the Bombard began attacking the Heavy Cannon. This is realistically possible due to the Heavy Cannon's smaller penalty versus other artillery and its greater rate of fire. Other common factors such as battlefield confusion, varying levels of micromanagement skill and line of sight advantages allow this scenario to occur frequently. The population cost of this unit is 7.
The Heavy Cannon has a base cost of 200 wood and 600 coin, and a train time of 115 seconds (86.25 seconds with "Engineering School" or "TEAM Engineering School" Home City Card, 69 seconds with both), while the Factory generates 5.5 (7.15 with the respective improvements) resources every second.
Therefore, a Factory producing a Heavy Cannon uses up 632.5 resources (475.75 with "Engineering School" or "TEAM Engineering School", 379.5 with both); with all three of the respective improvements, the value goes up to 822.5 (618.475 with "Engineering School" or "TEAM Engineering School", 493.35 with both).
This means for the majority of civilizations, especially those lacking significant damage potential with Heavy Cannon, it is very economically damaging to create them. Improvements and Home City Cards that reduces artillery train time will also affect the Factory, whereas no economic cards do the same. With "Engineering School" or "TEAM Engineering School", the bonus for Heavy Cannon is only 15% whereas regular artillery will train 70% faster (30% faster for civilizations lacking their "Engineering School"), fielding much quicker.
According to pre-release screenshots, the Heavy Cannon would be available to the British. There are unused voice files for British Heavy Cannon in the game files and in the Scenario Editor, which are the same voice files used by the Rocket.
The logistics of moving, maintaining, positioning, aiming, and firing artillery required a highly drilled and disciplined team with a sharp commander. In addition to the men and artillery pieces in his command, an artillery officer had to see to the horses used to haul the pieces around - sometimes up to six for heavier guns. When one side in a battle could field hundreds of artillery pieces, the logistics of just moving them into position were taxing. "Heavy Cannon" is a relative term, but in general, cannon considered 'heavy' were typically used as permanent gun emplacements to defend Forts and strategic locations.