R/C Warship Combat FAQ

Contents:

[Document Version: 1.01] [Last Updated: May_3_1995]


1. About the Author

R/C Warship Combat FAQ

Author: Frank Pittelli
E-Mail: pittelli@rssi.com
Date: May 3, 1995


2. Preface

In 1989 I became fascinated by an interesting, complex, and extremely challenging hobby known as R/C Warship combat. Over the years, people have continually asked questions about the hobby and this document contains a small fraction of the questions and answers. I hope that it encourages you to find out more about the hobby and to build your own warship and join in the battles.


3. Do the ships actually sink?

Yes. There is no challenge otherwise.

The ships are built to rigid standards that ensure that they can be damaged easily and can be sunk if sufficient damage is sustained. Low-powered BB cannons are used to poke holes in the 1/32" balsa wood that is used on the hull of the ship. Ships also have homemade bilge pumps on-board that can be used to pump out as needed.

However, if the rate of incoming water exceeds the pumping rate, the ship will fill with water and eventually sink.


4. What prevents a captain from pulling their ship out of the water before it sinks?

The rules!!!

By rule design, in order to take your ship off the water, a captain must start a 5-minute timer. During that 5-minute period, the ship cannot fire on any other ship, but it may be fired upon. When the timer expires, the captain can touch the ship and remove it from the water. Generally, experienced captains determine when their ship has suffered too much damage and begin their timers early enough to prevent the ultimate disaster: a sink.

On numerous occasions, ships have sunk a few seconds before the timer has expired.


5. What happens after a ship is sunk?

We retrieve it from the bottom of the lake. (One lady actually believed that we simply left them there and built another ship!!!)

Most battles are conducted on shallow ponds, which allow the captain to wade in and salvage the boat. Sometimes, captains attach floaters to the superstructure with a long, strong line, in case they can't locate the boat. On a couple of occasions, such lines have deployed during a battle, tangling in the props of one or more ships.


6. Are the electronic parts ruined when a ship is sunk?

Generally not. Most ships have "water-tight" boxes that surround the electronic parts. Some captains prefer to "water-proof" the servos and RX separately, in order to save space. In either case, even if the equipment gets wet, since all battles are conducted on fresh water ponds, the wet electronic parts can be disassembled and dried in the sun in about an hour. Experienced captains can sink in the morning, disassemble and dry everything and be ready to battle again in the afternoon.


7. Is the 1/32 hull sheeting waterproofed somehow?

That sort of sheet warps VERY easily, it seems to me that a few holes would ruin the hull for good. So do you coat the hull with some sort of waterproofing agent (inside and out?) or do you just build lots of spare hulls?

Lots of spare hulls??? We have some hulls that have been battled and repaired for 10 years!!!!

We generally apply a single layer of 000 silkspan to the inside and another layer on the outside, using either clear dope or lacquer. I prefer standard brushing lacquer because I can buy it in quart sizes and it doesn't stink as much as clear dope.

In either case, that is sufficient to waterproof the hull, given a coat or two of paint on the outside. Our rules require a specific "drop test" to ensure that hulls are not too hard, so it doesn't pay to use too much paint anyway.

When hull holes are repaired, we simply dab on some Ambroid glue or clear dope and apply a small silkspan patch. That drys in minutes and is waterproof as well. After a hull has had too much damage and there is more silkspan than balsa (roughly after 5 days of normal battling) we strip off the balsa and start over again. This process is easier if all of the ribs and deck rims have been sealed with polyester resin or epoxy before the balsa skin is applied.


8. How do you aim the guns?


9. Can each turret pivot/elevate or are they fixed in place?

Most guns are fixed in place and the captain steers the ship in order to aim them. This greatly simplifies the coordination needed and is generally considered the best approach.

Some battleships have rotating and/or elevating guns depending on the preference of the captain. I have used both and find rotating guns useful in some situations, like shooting a ship that is caught along shore, but generally they require more room in the boat and require more time to keep them working properly.


10. How fast can the guns fire? How many BBs at a time?

By the rules, a single gun can only fire one BB per throw of the joystick or button on the TX. In some ships, multiple guns are fired at the same time using servo splitters or hardwired solenoids.

The fastest firing sequence recorded on video showed a rate of roughly 5 shots per second, sustained over a 6-8 second period. Most of the shots were on target and the recipient battleship sank in less than 5 minutes with one of the strongest pumps running non-stop.


11. How old is the hobby?

It started in 1979 when two close friends floated a plastic model ship on a pond and took turns shooting it with a BB air rifle. A short while later, a R/C BB cannon was created and R/C Warship combat was born.


12. What is a complete R/C Warship?

  1. A hull, with 1/32 balsa sides, 1/144 scale
  2. Hardened superstructure
  3. BB cannons (1-7)
  4. CO2 storage tank (2-7oz)
  5. CO2 regulator (150psi max)
  6. CO2 values (one per gun, mechanical or solenoid)
  7. Batteries (Main motors, pump(s), RX)
  8. Main motors (gearing optional)
  9. Bilge pump(s)
  10. RX and servos
  11. Forward/Reverse Speed Control
  12. Prop(s) and shaft(s)
  13. Rudder(s)


13. How much does a first time captain have to spend?

Naturally, the total cost to build and operate a ship depends on builder skill and the components used. Almost everything can be built from scratch using common hand and power tools. Many components can also be procured from surplus catalogs, junk yards or flea markets for very good prices (I got 6 really good batteries at a flea market for $9 total). The amount of wood needed to construct a hull is relatively cheap. The most expensive part of the ship is the batteries (at least two sets of 8-20Ah) and the radio gear (4 channel minimum, 6 for battleships). A complete itemized cost list (built from scratch) is given below. Clearly, the first ship is the most expensive since you have to buy all the support gear initially. After that, almost everything, except the hull, can be re-used in another ship. Most veterans have a number of ships with interchangeable parts that are moved around as needed depending on the battle conditions and personal goals.

And don't let the initial cost discourage you. Many rookies borrow part or all of a ship from a veteran and battle it for a year. That leaves only the operating costs, plus time spent fixing the boat and repairing old parts. It's a nice way to try it out before spending too much money. (But remember, your time and pleasure are worth something too.)


Approx. Cost Of Rookie Heavy Cruiser
------------------------------------
 1. A hull, with 1/32 balsa sides           15.00
 2. Hardened superstructure                  5.00
 3. BB cannons (2)                          10.00
 4. CO2 Disposable Tank Adaptor             15.00
 5. CO2 regulator (150psi max)              15.00
 6. CO2 values (2)                          10.00 
 7. Batteries (Main motors, pump(s), RX)    40.00 
 8. Main motors (2)                          5.00
 9. Bilge pump (1)                           5.00           
10. RX and servos (4 channel)              100.00 
11. Forward/Reverse Speed Control            5.00
12. Prop(s) and shaft(s)                     5.00
13. Rudder(s)                                3.00
14. Paint and silkspan                      10.00
15. Glue                                    10.00
                                          ------- 
                           Building Cost   253.00

Operating Costs For Rookie Year (2 Regional Events)
-------------------------------
 1. IR/CWCC Membership                       6.00
 2. NAMBA Membership and Insurance          40.00
 3. Box of BBs (5000)                        6.00
 4. Disposable 2oz CO2 Cartridges (25)      50.00
 5. Battery charger                          5.00
                                          -------
                          Operating Cost   107.00

                        =========================
                        Total Rookie Cost  360.00
                        =========================

14. What type of speed control is needed?

Generally, experienced captains use a simple on/off, forward/reverse control made out of either a double-pole-double-throw-center-off switch or a pair of micro-switches mounted on opposite sides of a servo. The DPDT switch is simply wired so that the polarity is reversed when it is thrown in different directions. A servo is then used to throw the switch.

The pair of microswitches is wired so that when both switches are up, the negative side of the battery is sent to both poles of the motor. When either switch is depressed, the positive side of the battery is sent to one of the motor poles.


15. Where do the submarines come into it? :-)

At the bottom of the lake :-)

Actually, subs are allowed but they don't have enough firepower to make a difference and they are very small in our scale. Some have been used over the years, but primarily as a novelty. Battleships and battle-cruisers control the R/C combat seas.


16. Are the destroyers used and are they fast?

I noticed in the magazines that most of the ships are of the larger variety. Are destroyers ever used? (I know they are lightly armed and armored, but they are FAST).

They may be fast, but they are also very SMALL in our scale, which means that they are difficult to construct and outfit with the necessary systems. Nonetheless, there are 2 or 3 active at any given time, but they aren't very effective in battle because they only carry 25-50 BBs and they don't have the staying power to battle with battleships (as it should be).


17. Has anyone ever developed something like torpedoes?

Lots of nice ideas, but the rules (for safety reasons) prevent anything except BB cannons. In order to simulate the effects of a torpedo, destroyers and light cruisers are allowed to use "spurt" guns that fire multiple BBs at one time. That simplifies the design of the gun (making it lighter) and causes a larger hole on impact. Spurt guns were outlawed on larger ships 7 or 8 years ago because they simply caused too much damage when used in large numbers.


18. Where can I get an explanation and diagrams describing how the guns are made?

The IR/CWCC newsletter, called Hullbusters, is a great resource for technical tidbits. Also, you might want to contact warspite2@aol.com who created a builders handbook about 5 years ago and he distributes it for a small fee. It explains all of the essential system designs and decribes how to build basic systems.


19. How do you build the cannons?

The BB cannons are constructed using standard 1/4" compression fittings (commonly used in plumbing). Guns consist of the following components:

The magazine usually consists of a 9" piece of 1/4" copper tubing that is either straight or bent into a circle or spiral. At one end, straight or elbow fitting is soldered, allowing a cap to be screwed on and off. The other end leads into the interrupter and is attached using either a compression nut or solder.

The purpose of the interrupter is to select "one" BB at a time when a CO2 value is opened. It consists of a "tee" compression fitting, which has three openings, two on each end and one in the middle at 90 degrees to the other two. The magazine attaches to the one in the middle and the top opening leads to the breach. The bottom opening is used to house either a spring-loaded piston or two 1/4" ball bearings. Ball bearings require less precision and maintenance, but the spring-loaded piston allows more rapid firing rates. In either case, when gas is applied to the bottom opening (through the end cap) the piston or ball bearings rise up to block the opening from the magazine. This allows only one BB (the one on top of the piston or ball bearings) to move into the breach and fire. When gas the gas is released, the piston or ball bearings drop and another BB is allowed in the chamber above them, ready for firing.

A small piece of 1/4" copper or brass tubing connects the upper opening of the interrupter to the breach. The breach can be made using either a piece of surgical tubing (called a "geek" breach) or a compression fitting with an internal "o-ring". The geek breach is simpler to make, but it cannot be adjusted for "hardness" (the amount of pressure needed to make the BB fire) and the sometimes break. The o-ring breach works by forcing the BB through a rubber o-ring that is slightly smaller than the BB. As pressure builds behind the BB, it pushes the o-ring wider and eventually "pops" through, proceeding down the barrel. The o-ring breach is harder to "perfect", but it can be adjusted at lake side by adjusting the tension placed on the o-ring by the barrel. This is good for changing pressure conditions (pressures build with higher temperatures) but it requires constant attention before a battle.


20. What's the difference between the types of warships?

The rules govern the following critical parameters of all warships:

Ships are organized into classes, with larger ships getting more "units", where one unit can be used as either a gun or a pump. The following classes are common:


	Very Large Battleships	7 units
	Large Battleships	6 units
	Battleships		5 units
	Battle cruisers		4 units
	Heavy cruisers		3 units
	Light cruisers		2 units
	Destroyers		1 unit
Ship speeds are also divided into classes, with the following common classes (all speeds measured on a 100 foot course)


	Battleships (over 720')		24 secs	
	Battleships (over 600')		26 secs	
	Battleships (under 600')	28 secs
	Battle cruisers (over 660')	24 secs
	Battle cruisers (under 660')	26 secs
	Heavy cruisers (after 1922)	24 secs
	Heavy cruisers (before 1922)	26 secs
	Light cruisers 			23 secs
	Destroyers (over 300')		22 secs
	Destroyers (under 300')		23 secs

21. Some ships are unarmed freighters - what are these used for?

We have a game called "campaign" in which cargo ships are used to alter the strategies needed. Each fleet has to defend their own cargo ships, while trying to sink the opposing fleet's cargo ships or warships. It is an interesting game, but it requires a relatively large number of captains to make it interesting and it has a complex set of combat rules. In recent years, we have also developed some simpler versions that combine the tactics associated with cargo ships, without all of the original "campaign" rules. (In the standard campaign game, cargo ships can carry supplies or "troops" to multiple bases, and the troops can be used to seize an opponents bases.)


22. How do you score a battle?

Scoring consists of three things:

Battle damage is scored by counting the number of holes relative to an 1/8" wide water line tape, as follows:

Holes are not repaired in between "sorties" (2 per battle), but they are repaired in between battles.

Sink points are awarded to any ship that sinks because of battle damage, is declared sunk (without totally sinking) or is withdrawn from battle between sorties. Points are awarded based on the size of the ship:


	Class 7		1100 points
	Class 6		1000 points
	Class 5		 900 points
	Class 4		 800 points
	Class 3		 700 points
	Class 2		 400 points
	Class 1		 200 points
If a ship is "declared sunk" by the captain, the sink points are multiplied by 1.5. If a ship is withdrawn, full sink points are awarded.

Finally, if the ship breaks a specific set of battle rules (such as ramming another ship and causing damage) then penalty points are awarded depending on the severity of the infraction.

PS. The goal is to earn the "fewest" number of points.


23. How do you not get hit?

You stay out of the way of flying BBs.


24. I understand there is a trade-off between pumps and cannons - what is it?

Each ship has a fixed number of units and you can use a given unit either as a gun or a pump. Most ships generally carry one pump and the rest guns, although some battleships carry two pumps. You cannot exchange pump and gun units during a battle.


25. Where are the competitions?

Mostly in Maryland, Georgia, Texas, California, and Missouri. There are other smaller pockets of captains (and therefore local battles) but the sanctioned events are in the states listed above. "Regionals" are held over a weekend, generally in the spring and fall in each region (therefore the name). Attendance in 1995 should average about 10-20 captains at each regional.

The yearly national competition "NATS" moves around from year to year. In past years, it has been held in Bowie, Maryland (90 & 91), Orlando, Florida (92), Huston, Texas (93 & 94), and St. Louis, Missouri (95). NATS is a week-long event, held on the second full week in July. In recent years, attendance has been anywhere from 20 to 30 captains.


26. What's the difference between ball-bearing and BB cannons?

There seems to be a difference between ball-bearing and BB cannons. Apart from the size, what else?

Ball bearings have a lot more kinetic energy when fired, which causes more damage on impact. Ball bearing guns also use a simpler gun design because the depend on the "flow" of gas to fire the ball bearing.

BBs don't have as much power, which makes them safer for spectators. BB cannons also use the "pressure" of gas to fire the BB.


27. Exactly what kind of motors are used, and where can one get them?

Electric motors are used for propulsion and pumping. Generally people use 6 volt or 12 volt motors, depending on your battery preference. Motors can be acquired from surplus catalogs for a couple of dollars each. (The best price reported so far is $1.00 per motor). The RS550, RS540 and RS600 types are widely available and provide a range of torque and speed combinations. Many ships are now driven using 3-to-1 or 4-to-1 gear ratios in order to get more torque and less speed. This helps to turn the boat faster and gives better acceleration.


28. What propeller do you use?

What kind of prop (screw, whatever it's called) do you use, where do I get it, and how the heck do you get it attached to the boat with a waterproof outlet, so water doesn't get into the boat?

Many captains buy props from commercial model outfitters. I have found that such props are too expensive and tend to fall apart with heavy use (ie. grinding them into a gravel beach). I have been building my own props for the last 4 years out of a 3/8" diameter brass cylinder about 5/8" long. A 1/8" hole is drilled down the center and two or three slits are cut on the outside using a hacksaw blade or a dremel cutting wheel. Then, simply cut some triangular blades out of brass sheet, solder them in place and file them and bend them to your taste. At IR/CWCC scales and speeds, such rudimentary props behave just as good as the fancy store bought models.

All ship models use a "stuffing box" to allow the prop shaft to pass through the hull of the boat. Most people use an 1/8" brass rod for the shaft and a 3/16" brass tube for the shaft housing. A small piece of 5/32" tubing is solder inside the ends of the 3/16" tube to support the 1/8" shaft. If a little bit of grease or vasoline is inserted into the tube before the prop shaft, then no water will be able to force its way up the tube. (By the way, this is essentially how real prop shafts are installed also.)


29. Are there any images I can see?

Are there any GIF or JPEG images available for FTP of close-up pictures of the INSIDES of your ships, so that people like myself can get a good idea of just how this is done?

A number of JPEG format pictures were posted by Kommodor@aol.com to the alt.binaries.pictures.misc newsgroup on May 1, 1995.

(From filipg)

These are also available (FOR A LIMITED TIME) for those on the World Wide Web (WWW) at URL:

http://alpha.smi.med.pitt.edu:9000


30. What kind of frequency range do I need to use to control a ship?

(Can I use my airplane radio?)

Generally, you should use channels in the 75Mhz region, which are considered ground and sea frequencies. There are also a few channels in the 27Mhz band which can be used.

The AMA frowns on the use of airplane frequencies for anything except airplanes. Practically speaking, however, if you don't see or hear an R/C airplane overhead and you know that there are no landing fields within a few miles, then there isn't any reason not to use an airplane freq.


31. Any gotchas in building a first ship that the old, wise, sea-dogs can warn against?

Don't spend too much time on fine joints and precise interior hull work. After a season of battling, most warships have under-gone a series of re-designs to move systems around and work out all of the problems. Furthermore, any fancy super-structure work will almost certainly be blown to pieces, no matter how strong you think it is.

Keep everything as simple as possible and work on one system at a time until it works to your satisfaction. I always build things in the following order:

That way, you can determine where everything goes and can test drive the ship without worrying about guns and CO2.


32. Can I do 'damage control' and improve my ship?

I was just curious, what if anything can be done on the ships re: damage control, I know you use pumps to get rid of the water, but could you break up the hull into 'subsections' with waterproof bulkheads between thus keeping a hole from flooding the whole boat (and having some sort of tubes interconnecting allowing you to pump out just the one section)?

I think filling all hollow areas with styrofoam would be an excellent idea.


Both ideas have in fact been used and are too varying degrees covered by the rules.

Watertight compartments
As in real warships, the proper use of watertight compartments can make a ship VERY difficult to sink. Clearly, if such compartments were used in our hobby, then we would never be able to sink anyone. And since the purpose of our hobby is to sink someone and to stop yourself from being sunk, the use of watertight compartments has been ruled illegal for well over 15 years. In fact, the rules stipulate that water most flow freely throughout all parts of the ship.

Styrofoam
The use of floatation material to keep the ship afloat is illegal, because otherwise no ships would sink and no fun would be had. However, styrofoam can be used (or any material for that matter) to channel water into the middle of the ship. Spray-in foam is used now by many battleship captains to keep water from pooling in the "bulge" areas of a large ship. Otherwise, a list would develop and the pump would not be effective. However, such material must not prevent a BB from causing a hole in the side of the ship and it must allow water to freely flow.

Also, while we're on the subject, the rules prevent the use of self-sealing hulls and inner hulls as well.

All of these restrictions have been developed to guarantee that ships CAN sink. It might not be obvious, but R/C warship combat isn't any fun unless you can sink someone else AND you can be sunk by someone else. In fact, you haven't "tasted combat" until you've escaped sinking by a few seconds or fractions of an inch.


Please check attribution section for Author of this document! This article was written by filipg@repairfaq.org [mailto]. The most recent version is available on the WWW server http://www.repairfaq.org/filipg/ [Copyright] [Disclaimer]