A wooden tall ship, like the HMS Victory, USS Constitution, or Patrick O'Brien's Surprise strikes an immovable object (i.e. rocks) rising out of the sea.

In many nautical series I've read, colliding with anything would be an EXTREME hazard. Masts go by the board, large holes punching through the hull or even breaking the keel. The problem is, I haven't been able to quantify the variables (i.e. the mass of the ship, its velocity, tinsel strength of the woos or the structural integrity of the ship's overall design).

As for the immovable object, that's simply an aspect of the story I'm currently working on in which a character can make themselves completely immovable, on a quantum level. Said character leaps out of their own ship, freezes in space in front of a pursuing enemy ship and lets it crash into them. That's the real premise. My real question is, would this be a viable tactic each time, or is there a slow enough speed at which the ship can be moving where it's mass and momentum would do only negligible damage?

I suppose this will all be opinion-based and if I made a mistake as a newcomer posting this here, I do apologize.


closed as too broad by Aify, Samuel, HDE 226868, Monty Wild, JDługosz Aug 21 '15 at 0:16

Please edit the question to limit it to a specific problem with enough detail to identify an adequate answer. Avoid asking multiple distinct questions at once. See the How to Ask page for help clarifying this question. If this question can be reworded to fit the rules in the help center, please edit the question.

  • $\begingroup$ What kind of ship? A racing sailboat at a reasonable speed will decimate itself on an immovable object (read: on the rocks) because the sailboat traded off EVERYTHING for more speed. A military frigate, which is designed to survive in wartime conditions, may fair much better. $\endgroup$ – Cort Ammon Aug 18 '15 at 4:06
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    $\begingroup$ This is a typical "too many variables" type of question. As Cort Ammon says, the size and construction of the ship are an important factor. Also what are you running into? Running aground on a sand bank will produce a different result to being driven into a cliff. Also its not unusual for the bulk of the damage to be done by wave action after the initial collision. $\endgroup$ – Steve Bird Aug 18 '15 at 6:04
  • $\begingroup$ i assume you were looking for the maximum speed. the minimum speed would be zero: no speed = no energy = no damage. $\endgroup$ – Burki Aug 18 '15 at 9:19
  • $\begingroup$ Is it an unstoppable ship? $\endgroup$ – Serban Tanasa Aug 18 '15 at 10:59
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    $\begingroup$ Are we ignoring the fact that nothing is immovable? $\endgroup$ – HDE 226868 Aug 18 '15 at 21:24

It depends on the direction of the strike. Head on, ships can be made incredibly strong. In ancient times, warships were designed for head on collision with other ships in order to sink them. Their masts were usually quite stubby however and the main propulsion came from the oars. enter image description here


There is a lot of momentum in a ship, and even worse if the hull gets breached then water pours in and the ship is going down. In other words basically no speed is safe to collide, although obviously the slower you are going the less dangerous it is.

Remember that waves will be lifting you up and down against whatever you hit and smashing you into it even after you have stopped. This is why boats have fenders.

So they wouldn't lose masts (at least immediately) but even at slow speeds they are likely to smash open a large hole. Once a hole is formed the boat will only force itself further and harder onto the rocks as well since it is losing buoyancy and still being forced by the waves.

  • $\begingroup$ In respect to losing a mast, it depends on the construction of the vessel. During the age-of-sail, in most large ships the masts were not secured directly to the hull. They were kept in place by their weight and by the rigging. If the ship was rocked violently either by a rogue wave or collision it was entirely possible to "roll out" the masts. $\endgroup$ – Steve Bird Aug 19 '15 at 7:15

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