Documentation file for HMS Surprise (version 02.12.14)
Table of contents
1. Introduction
2. The Displays
3. Controlling the ship
4. Pausing, Saving, Loading
5. Changing the environment
6. Performing evolutions
7. Definitions
Text in red refers to parts of the simulator; terms in green are defined at the end of this document.
1. Introduction
1.1 Before you start
HMS SURPRISE is designed for a screen resolution of 800*600 pixels and 16-bit colours. You can also use a resolution of more than 800*600 pixels, but then the simulator will not use the whole screen; with a resolution of less than 800*600 pixels you will not be also to view the entire simulator at once. If you use less than 16-bit colours, colours from the standard Windows palette replace the normal colours.
Although designed to be used in a maximized window, you can run the programme in a smaller scrollable window.
See the About box for the version number of this release of the programme. Check http://home.wxs.nl/~pdavis for newer versions. E-mail me with any comments.
1.2 Overview
The simulator consists of a number of displays, which provide information about the status of the ship, and controls and a menu, which allow you to sail the ship or to alter the environment or the information shown on the displays.
Except when paused, the screen is updated at intervals of about 0.5 seconds, whilst the various parameters which define the state of the simulation are recalculated as often as possible (on a reasonably fast computer at intervals of about 0.05 seconds).
The displays are:
The following controls are used to sail the ship: sliders to move the yards (on the fore, main and mizzen masts) and the mizzen boom, a slider to move the helm, a slider to veer and haul the jib, and buttons to activate the "automatic helmsman" and the "automatic yardsmen".
The other buttons are used to adjust the displays.
The menu items are:
2. The Displays
2.1 The Plan View
The display immediately under the menu shows the ship viewed from above. The small yellow circle is the centre of rotation. The rudder is shown in light blue. The yards (including the mizzen boom) are shown in yellow. If the jib is set, its foot is shown in white. The pink cross indicates the position of the centre of effort of the sails.
The actual direction of the wind is shown by a dark green arrow; the apparent direction of the wind for an observer on the moving ship is shown by a pink arrow.
You can alter the information shown on this display by selecting Planview in the menu (the currently selected option is shown checked in the menu):
2.2 The Sail Plan
The sail plan display is to the right of the plan view display. Select Sailplan in the menu to toggle between two different views:
The dimensions, maximum number of reefs, and status (set, reefed, furled, or blown out) of the individual sails are shown on the conventional sail plan. Square sails are shown light grey (if set) and fore-and-aft sails dark grey. The display shows the outline of furled (or reefed) sails against the sky background. Sails which have been blown out by the wind are shown dark red.
If the conventional display is selected, individual sails can be set, furled or reefed by a single (left) mouse-click on the sail. Sails which can only be set or furled (but not reefed) toggle between the set and furled states when any part of the sail is clicked. On sails which can also be reefed, a reef is taken in (or a fully reefed sail is furled) or a reef is let out (or a furled sail is loosed to the fully reefed state) by clicking on the appropriate part of the sail. To fully set a furled sail with three reef bands, you thus have to click four times.
Note: To furl or set the jib, you must click on that part of the sail above its foot (thus not in its head).
Sails blow out if the wind (actually: the apparent wind) speed is too high. The exact speed at which any individual sail blows out is dependent on a number of factors:
If sails are blow out, then they must be furled before they can be reset.
You can make more sail or reduce sail in a programmed manner using the Increase Sail and Decrease Sail buttons above the top left corner of the sail plan; there are nine possible configurations between all sails set and all sails furled.
You cannot change the state of individual sails when the perspective view is selected (although you can use the Increase Sail and Decrease Sail buttons); clicking anywhere on the perspective view restores the conventional sail plan to enable such a change.
2.3 The Map
Latitude and longitude are measured in nautical miles; the simulation always starts with the ship at the origin of the coordinate system (the position: 0 miles North, 0 miles East).
The map, to the right of the sail plan shows the current position of the ship (yellow spot) and the track which has been followed (grey line). You can zoom the map in and out (by a factor of 5) using the buttons above the map: the width of the display can be varied between 0.04 and 25 nautical miles. If the ship moves off the edge of the map, the later shifts (by a half map-width) in the appropriate direction if the check box under the map is selected. You can manually pan the map by (left) clicking one or more times with the mouse on the map near its edge in the appropriate direction; this automatically deactivates the ship tracking check box. Click the check box to reactivate automatic tracking. You can also toggle tracking of the ship on and off by selecting Map in the menu.
The width of the map display, and the coordinates of the top left and bottom right corners are shown near the map.
The track display retains the last 2000 positions of the ship (this corresponds to about 16 minutes sailing time). Select Map in the menu to clear the displayed track on the map.
2.4 The Stern View
The stern view, below the plan view, displays the angle of heel of the ship on a simplified view (hull and main mast) from astern. Except when the yards are squared, no sails are set, or there is no wind, a pink arrow indicates the height of the centre of effort of the sails and the direction of the leeward component of the wind's action.
The ship state display (bottom left) shows:
Under this display a number (without any caption) shows the actual number of recalculation cycles per second.
Any red letters (FLRH) to the right of this number are warnings of acceleration damping, resulting from inappropriate values of ship dynamic properties.
2.6 The Sail Parameter Display
The sail parameter display is the numerical display on the outline of the ship on the lower central screen. This display shows a selected parameter for each of the sails (and, where appropriate, for the rudder). Select Parameters in the menu to change the parameter shown.
The following parameters can be chosen:
If one of the four thrust parameters has been chosen, a summary table under the display shows the total thrust, the total drag and their resultant.
The colour of the parameters on the sail parameter display indicates the state of the different sails:
Notes: Sails that are ashiver generate less thrust that would be expected theoretically. Sails that are taken aback start to shiver much later than sails with the wind from the normal direction because the mast, being then to leeward of the sail, tends to keeps the sail in form.
2.7 The Status Message Display
Warning or informational messages from the programme are shown here. Messages are announced by a tone and scroll off the display after ten seconds.
3. Controling the ship
3.1 The Yards
You select the position of the yards using the Fore, Main, Mizzen and Mizzenboom sliders; the selected and actual angles are shown above the sliders (0 degrees is square for the square sails and fore-and-aft for the mizzen course). The yards are not braced round instantly: rapid large changes of the slider position take some time to be effectuated.
Use the check boxes above the sliders for the fore and mizzen yards to "couple" these to the main yards; coupled yards all respond when one of their sliders is used (this is useful when carrying out evolutions, for example tacking).
Use the Yardsmen button to activate and deactivate the "automatic yardsmen" who can keep the yards at an optimum angle for forward motion (the apparent wind bisecting the angle between the yards and the keel of the ship). If the yardsmen are activated the text under the button changes from "(await orders)" to "man braces", and the colour of the yard names by the sliders changes from black to grey to indicate that the sliders cannot be used (if you try, the yards will not respond and the slider will spring back to its original position when released).
3.2 The Jib
The sheet of the jib can be veered (to increase the angle between the foot of the sail and the keel of the ship) or hauled (to decrease this angle) using the Jib slider. The clew (aftward corner of the foot) of the jib is always on the leeward side of the ship; when the ship goes through the wind, the clew automatically flips over to the (new) leeward side.
When the jib is furled it is automatically hauled right in (jib angle is 0 °).
Hauling and veering the jib is a useful way of making small adjustments to the rotational forces acting on the ship: avoid an excessive helm angle when sailing close to the wind by hauling the jib in.
Use the buttons under the Jib slider to change between the Large, Working and Storm jibs; this is only possible when the jib is furled.
3.3 The Helm
Use the Helm slider to alter the position of the helm. Note that moving the helm to port moves the rudder (and thus the head of the ship) to starboard. As is the case with the yards, the helm takes some time to effectuate large changes.
Use the Helmsman button to activate and deactivate the "automatic helmsman". When the button is pressed a dialogue box appears at the place of the sail display. You can enter a heading to steer, or change the indicated heading (in steps of 1 degree) using the "<" and ">" buttons. Then press the OK button to activate the helmsman (or the Cancel button to return to manual control). You can also select a heading by clicking with the right mouse button on the plan view near the edge of the display (the bearing under the mouse cursor is shown temporarily just above and to the right of the plan view) to open the dialogue box with the appropriate heading already selected.
When the helmsman is activated the text under the button changes from "(await orders)" to "go to <the selected heading>", and the ship turns to the selected heading. When the ship reaches the selected heading, the text under the button changes to "steering <the selected heading>". The ship will now maintain the set heading even if you change the sail settings or the wind direction (possibly after an initial deviation). If the heading deviation exceeds 3 degrees, the text under the button temporarily changes back to "go to <the selected heading>".
When the helmsman is activated the colour of the word Helm by the slider changes from black to grey to indicate that the slider cannot be used (if you try, the helm will not respond and the slider will spring back to its original position when released).
Do not activate the helmsman immediately after a sudden helm change (when the state of the ship may not yet reflect the current helm position); under extreme conditions the helmsman may not manage to get onto the correct heading.
When first activated, the helmsman observes if the ship is already rotating towards the desired heading; if this is the case, he does nothing and waits for the ship to reach that heading. If the ship is rotating away from the desired heading, he applies helm as appropriate. When the ship reaches the desired heading, the helmsman calculates the amount of helm needed to bring the rotational forces to zero and applies this. If the ship drifts off the heading he applies one degree of helm correction. If the ship drifts more than three degrees off heading (generally only due to external circumstances), he begins anew.
Activating both the yardsmen and the helmsman together assures optimum performance (but leaves less for the captain to do). If you instruct the helmsman to steer a heading requiring the ship to tack, this evolution will be carried out automatically if both helmsman and yardsmen are activated. If you instruct the helmsman to steer a heading too close to the wind, he will steer the best possible heading (close-hauled).
If the ship is sailing close-hauled and the wind direction changes, the helmsman will automatically adjust his heading to prevent the ship from being taken aback.
Use the Helmsman button and then the Cancel button directly to deactivate an activated helmsman.
4. Pausing, Saving, Loading
4.1 Pause, restart or exit the programme
You can use the Pause button to suspend the programme; the caption of the button changes to Restart; press it again to restart the programme.
Select Files | Exit in the menu to stop the programme.
4.2 Save a situation
The programme starts with a default situation (default ship heading south east with wind from the south west). You can save a situation (all current ship and environment properties) to rerun later by selecting File | Save or File | Save As in the menu. You should save the situations in the folder that also contains Surprise.exe.
The situation files have an extension .ssf (Surprise Situation File) and are readable ANSI-files (you can use an ANSI editor like Wordpad to edit them if you are reasonably careful; each line must contain a parameter name, a colon and a value).
Note that the position of the ship is not saved. When you reload a saved situation, the newly loaded ship springs to the origin of the coordinate system.
You can reload the default configuration by selecting File | New in the menu.
You can load a previously saved situation by selecting Files | Open in the menu. The current situation is replaced without being saved.
5. Changing the environment
5.1 Ship Dimensions
Select Edit | Ship dimensions in the menu to modify the physical properties of the ship. These are (all dimensions are in feet):
The changes you make in this (and the other dialogue boxes described below) are normally implemented immediately (to enable you to observe their effects). If you dismiss the dialogue box with the Cancel button, however, the original values are restored. Use the OK button to dismiss the form and retain the new values for the present session. If you want to retain the changes permanently, you must save the current values before quitting the programme.
If you don't want the changes to be implemented immediately, use the Pause button before invoking the Edit menu.
You may continue to use the ship controls (for yards, helm etc.) while a dialogue box is in use; move the box out of the way if necessary by dragging its caption bar.
Select Edit | Ship dynamic properties in the menu to modify the following factors which determine the behaviour of the ship:
Note: using inappropriate values of these parameters may make the ship unsailable (or even cause the programme to crash). The programme does prevent the linear (fore/aft and leeway), rotational and heeling accelerations from becoming unrealistically large (greater than 2 kt/sec or 2 °/sec/sec). If such a constraint is being applied, one or more red letters (F=fore/aft, L=leeway, H=heel, R=rotation) appear at the bottom left of the screen. If these warnings appear more than occasionally, you should adjust the dynamic parameters.
5.3 Square sails
Select Edit | Square sails in the menu to modify the following dimensions and properties of the 11 square sails (and the mizzen sail):
5.4 Stay sails
Select Edit | Stay sails in the menu to modify the following dimensions and properties of the large, working and storm jibs, the only stay sails implemented in the present version of the simulator:
Note: the leading edge of the jib runs along the jibstay, the top end of which is attached to the fore mast at the level of the fore mast topsail yard.
5.5 Islands
Select Edit | Islands in the menu to modify the position and size of the islands:
The selected island is shown dark red on the Map; you can also relocate a selected island by right-clicking on the new location (after disabling ship-tracking if necessary).
Note: remove an island by setting its radius to less than 0.0001 miles.
Note: you can in fact sail over the islands with impunity (they are, after all, only virtual islands), a tone will however sound to draw attention to your lubberly behaviour.
5.6 Wind
Normally the wind blows with a constant speed from a constant direction; the direction from which the wind blows is shown by a dark green arrow on the plan view. The wind direction and speed are also shown in dark green in the basic parameter display.
You can change the wind direction and/or speed by clicking with the left mouse button on the plan view, in the direction you want the wind to come from (the bearing under the mouse cursor is shown temporarily just above and to the right of the plan view). Click near the centre of the plan view if you want to change the wind speed, but not the direction. A dialogue box now appears at the place of the sail display. You can adjust the direction you want the wind to come from and the wind speed by entering new values or by changing the indicated values (in steps of one degree or knot) using the "<" and ">" buttons. You can also use the same procedure to specify the rates of change; the "<" and ">" buttons change these by a factor of two. Press the OK button to implement the changes (or the Cancel button to ignore them).
Wind speed can vary between 0 and 70 knots. With a 50 knot wind on the beam the ship can (assuming you fit her with upper sails which, in contrast to real ones, don't get blown out long before that), almost be driven onto her beam ends (angle of heel almost 90 degrees). Unlike a real ship, the simulator is fitted with watertight gunports and hatch covers, and will survive this harrowing experience unscathed.
6. Performing evolutions
6.1 Introduction
The following instructions should enable you to perform common evolutions. I suggest you first try them with royals furled, the working jib set and a wind speed of 20 knots. All the evolutions should start with the ship sailing close-hauled and carrying some weather helm; it is the intention to end the evolution with the ship sailing close-hauled on the other tack (with the wind from the other side of the ship).
These evolutions are described in detail in chapter 12 of John Harland's (highly recommended) book "Seamanship in the Age of Sail".
Note: The "afteryards" are the main and mizzen yards together; the "headyards" are the fore yards; the "spanker" is the mizzen course.
When you have completed the evolution, use the map to view and evaluate your track.
6.2 Tacking
Tacking is the change to the opposite tack whereby the head of the ship passes through the wind. This is the preferred method because least progress to windward is lost. A good ship can bring her head through the wind without making sternway. This is not the case for the standard configuration of the simulator; if you increase the value of the Mass Factor to 10 and reduce the values of the Rotational Inertia, Heel Angle and Heel Inertia Factors to one tenth of their standard value (in effect increasing the linear inertia, but not changing the other inertias) the ship will only come to a standstill for a few seconds (this will however make the ship somewhat more difficult to steer, particularly when close-hauled).
Tacking is not always successful; in that case it will be necessary to wear or boxhaul.
To tack, proceed as follows (the procedure is carried automatically if you have activated both the automatic helmsman and the automatic yardsmen):
6.3 Wearing
Wearing is the change of tack where the stern of the ship passes through the wind. This evolution will always be successful, but progress to windward will be lost:
6.4 Boxhauling
This is generally used as a recovery from a failed attempt to tack; the ship initially makes sternway to bring her to a stop with the wind aft: