Possible Clues:

• Increase by periodic additions
• Grow or accumulate, say interest
• Grow, as capital
• The sound of a complement will increase like this
• Build up interest in a working group, say
• Build up, as revenue
• This will grow to be enough to manage the ship, by the sound of it
• Shipping company heard to make a profit
• Accumulate or amass like interest
• A thousand is placed around the hand-warmer for this little sitter