I'm working on my Marienburg Landship, and to be quite honest I feel the Forge World rules are somewhat lackluster. So here's my take:
Marienburg Landship (300 points)
Unit Type: Chariot (3+ armour save)
Profile M WS BS S T W I A Ld
Landship 2d6+3 - - 6 7 12 - - 8
Captain - 5 5 4 - - 5 3 -
Engineer - 3 4 3 - - 3 1 -
First Mate - 4 4 4 - - 4 2 -
Gunnery Chief - 3 3 3 - - 3 1 -
Crewman - 3 3 3 - - 3 1 -
Crew: Captain, Engineer, First Mate, Gunnery Chief, 2 Crewmen
Weapons: Handgun, brace of pistols (all crew).
Special Rules: Terror, Unbreakable
Marvel of Engineering: The landship has the Random Movement (2d6+3) special rule. It may not pivot freely but is limited to pivoting once up to 90 degrees port or starboard before moving. It may not flee, pursue or overrun. Forests, swamps and buildings count as impassable terrain for the landship.
Lumbering Behemoth: The landship is considered to have an Initiative of 1 when required to make an Initiative test.
Extremely Flammable: The Landship carries large amounts of gunpowder. The landship has the Flammable special rule. In addition, all flaming attacks against the landship may re-roll failed To-Wound rolls . If the landship loses its last wound to a flaming attack (or a batch of attacks that includes any flaming attacks) it will explode spectacularilly: All units within 2d6 inches of the landship suffers 1d6 Strength 6 hits with the flaming attacks special rule.
Stable Fighting Platform: For the purpose of shooting the landship does not count as having moved. Also, the crew may use their brace of pistols in close combat as if they were models on foot.
Culverin: The culverin uses all the rules for a cannon with the following exceptions: It has Strength 7, a range of 24 inches and the Armour Piercing and Multiple Wounds (1D3) special rule. Any grapeshot is resolved at Strength 4. If the culverin suffers a misfire do not roll on the misfire chart; instead roll 1d6. On a roll of 1-2 the cannon is destroyed and cannot be used again for the rest of the battle, and the landship suffers 1D3 wounds. On a roll of 3-6 the shot has no effect.
Gunnery Chief: While the landship has 10 or more wounds remaining it may re-roll the first of the artillery dice for each shot with the culverin.
First Mate: While the landship has 8 or more Wounds remaining all close combat attacks against the landship are resolved against the First Mate's Weapon Skill. Otherwise, resolve attacks against the Weapon Skill of the crewmen.
Engineer: While the landship has 5 or more Wounds remaining it has the Regenerate (5+) special rule.
Captain: While the Landship has 3 Wounds or less remaining it can issue and must accept challenges as if it were a character. Only the captain fights in the challenge so his Weapon Skill is used instead of that of the crew. Notice that the challenge will continue until either side is dead, even if the landship should recover any Wounds.