Despite the urgency of the situation and their maximum speed of around 25 knots, the ships travelled at a steady 10 knots--running at high speed used significantly more coal, so to complete the long journey it was necessary to travel at the most economic speed.
The ships travelled at a steady 10 knots --. This was despite the urgency of the situation. This was despite their maximum speed of around 25 knots. The ships were running at high speed. This was despite the urgency of the situation. This was despite their maximum speed of around 25 knots. This high speed was used significantly more coal, so to complete the long journey. It was necessary to travel at the most economic speed the long journey.