Possible Clues:

• Royal Engineers rigidly enforced limit
• Confine this to being about to get narrow-minded
• That's about a severe way to keep in bounds
• Place limit on extremely repressive firm
• Confine this about the stern at the end
• It's about to get severe to stop you going further
• That's enough to make Con fine
• Control
• 'Restrain, limit (8)'
• Regulate rough critters