by Steven K. Roberts
San Diego, California
June 7, 1993
The Boatlab Materializes!
Well, I have good news! It has been one year since I posted “LEVIATHAN: Call for Discussion” to the Technomads alias and started tossing around ideas for this new project. A few months later, I began the quest for a host lab, convinced that my next mid-life career change would involve this boat. After a few false starts and a number of interesting offers (most as a result of a posting to this wonderful online mailing list), the problem has been solved.
I am pleased to report that I have just arrived in San Diego with nearly everything I own, with the intent of spending the next 2 years building the new machine at the Scripps Institution of Oceanography and UC San Diego campus. The setting is nearly perfect, and can be described as a high-tech blend of academia and real engineering… conveniently located on an idyllic beach with year-round optimal weather. It’s a bit early to report on the nature of relationships and such, but the general scenario is direct involvement with the oceanography community as well as close connection with the engineering departments at UCSD (as adjunct faculty). The Microship will be a multidisciplinary student-project platform, and the affiliation gives sponsors the option of working through education-support channels.
The lab itself is not yet precisely defined — more on that next time. As of this date, I have completed the speaking tour, returned Sok Sun to her academic life in L.A., offloaded a U-Haul truckload of bikelab equipment into what will later become the fiberglass shop, established an office in the engineering building, and am beginning the process of moving into this diverse community (including a quest for a place to sleep!). Stay tuned…
While all this has been going on, I’ve been working on Microship design, and I can FINALLY start telling you about it in something other than rhapsodic, poetic terms…
Microship General Description
Stated simply, the whole idea of the Microship is to extend the design principles of BEHEMOTH — a human/solar-powered mobile workstation designed to render my physical location irrelevant.
The new project is an aquatic tool for nomadness, significantly updated to represent the capabilities of 1993-1995 technology. Once the lab is in place, I will work for 2 years with the development team, then launch in 1995 for a few years of open-ended adventure linked to the network more tightly than ever before. Much of this connectivity is devoted to the original objective of maintaining stable publishing and personal relationships while traveling full-time. This is no small matter: most serious travelers report inability to remain current with news and industry developments, poor productivity, loneliness, and homesickness as side-effects of being on the move for years. I have solved these problems by depending on network connections to move my perception of stability into “Dataspace,” and the new project will extend this metaphor by radically increasing communication channel bandwidth and the sophistication of front-end software tools.
New motives have surfaced as well. The Microship will carry a suite of environmental data collection sensors, and will transmit telemetry blocks to schools, an FTP server, and BEHEMOTH in its new home at the Computer History Museum. While I am not pretending to perform any kind of comprehensive survey, this will nevertheless yield interesting data for education, with possible spin-offs in the form of an RF-linked data collection package useful to student groups for local analysis of environmental conditions.
Hull And Mechanical
After exploring a number of configurations and brainstorming with naval architects, kayak designers, sailors, and mechanical engineers, Microship overall design has stabilized into a human/solar/sail- propelled trimaran consisting of three sea kayaks — a large, beamy double (about 22′) for the center hull, and two sleek singles (about 17′) for the amas, or outriggers. These are linked by folding solar panel arrays totaling 664 watts (about 7/8 hp) of capacity in full sun, occupying approximately 4×8′ on each side plus packaging overhead. If you envision a big double kayak with a sail, joined to a pair of medium kayaks by a couple of solar ping-pong tables, then you have a rough idea of the general plan.
Numerous hatches and sealed equipment bays in all three hulls provide space for packs, comm/nav gear, water processing, food storage, tools, and so on. Given the stresses encountered in rough seas, the composite layup will be considerably stronger than that of a normal lightweight kayak, with special attention to stress transition areas surrounding the attachment points for the stainless steel folding beam assemblies.
This architecture offers a number of features and operating modes:
- NORMAL. The boat will be extremely stable, allowing easy movement among hatches and cockpits. In a standard kayak, retrieving gear from a hatch is a risky operation — this will be more like a floating platform. Controlled flexion in the outrigger arms will prevent excessive stress in rough seas.
- COMPRESSED. To fit into standard berths and between narrowly spaced bridge supports, the solar structures can be “accordioned” and the hulls juxtaposed by folding a spring-loaded stainless steel support frame, yielding a 7′ beam.
- WATER BIVOUAC. Conditions may force alternative overnight accommodations: the solar surfaces will be backed by aluminum honeycomb panels strong enough to support human weight. Two rectangular dome tents will fit on these surfaces, linked by a “hallway” covering the main console area.
- STORM. In heavy weather, there is reason to be concerned about large flat surfaces, especially when heavy swell can close off one end and create an air pocket. The solar panels fold independently of the outrigger support structures to minimize the impact of wind and dumping seas.
- BASE CAMP. With its shallow draft, the boat will be ideally suited to beach camping, when the smaller kayaks can be disconnected to provide seaworthy vehicles for local exploration or errands.
- EMERGENCY DINGHY. The flexibility of this design allows either kayak to be disconnected at sea and paddled ashore (or used for escape in the event of catastrophic damage to the main hull). In surf conditions dangerous to a multihull, all components can be disconnected, linked by lines, and hauled in (the honeycomb-backed solar panels will float) after the main hull is surfed to shore. This spectacle is reserved for emergencies only…
- ROAD. Finally, the realities of full-time nomadics dictate frequent visits to host sites. The three hulls will nest in a triangle, with all-terrain wheels and a carriage assembly to allow towing behind a vehicle or, for modest distances, the human pilot(s) linked by yoke and hitch. Still considering the tow bicycle, but… The main hull will have a custom deck plan, though the singles should be more or less standard with the exception of outrigger- support fixtures. In front of the main cockpit, a raised console will carry Mac, video, and control system LCDs, as well as the Marine VHF panel and a small cluster of minor controls. The bulk of the electronics will be in a sealed hatch, communicating with the console via the on-board network. Other major deck fixtures include whip antennas, satellite earth station, GPS antenna, a glass video turret, lights, drogue, anchor, compass, and the usual suite of survival and safety features such as grablines and cleats.
- Propulsion is based on three power sources. On sunny days, the 664- watt solar array will provide approximately 50 pounds of thrust from a resting state, yielding cruising speed estimated in the 4-5 knot range via a thruster integrated with the rudder assembly. Power can also be provided by two sets of pedals linked to efficient generators, yielding 100-150 watts per person. While this is about 25% less efficient than a direct mechanical linkage, the weight and complexity are dramatically reduced (and integration with the power management system allows battery recharging using human power under any conditions). Finally, a sail rig can be deployed to allow wind power — the configuration is yet unknown, though good alternatives of appropriate scale are available (roller-furling, stock sailboard rigs, or Balogh kayak sails).
Electronics packaging will depend upon a few tricks to minimize the impact of the fiercely corrosive seawater environment. The control console and main equipment bay will operate at about 3 psi above ambient, provided by a small electric pump (with a Schrader valve for bicycle-pump backup) followed by a desiccant cartridge and fine-mesh filter. The intent here is to prevent the enclosures from thermally breathing moist, salt-laden air in the event of a leak — they will outgas and sound an alarm when the control system notices pressure drop uncorrelated with temperature change. Eventually the desiccant will become saturated, and I’ll dry it over the camp stove.
Related packaging issues affect every part of the design, and we will make liberal use of undersea connectors, sealed or potted subassemblies, and a mineral-oil bath for components that need to be serviceable but don’t justify inclusion in the pressurization system. (One of the nice things about working with oceanographers at Scripps is that they have already developed effective solutions to these problems…)
Computer Systems And Applications
This is an area that involves extensive detail, but for purposes of this overview I will keep it at the summary level. Basically, there will be two classes of computers on board — the high-level systems and the low-level control network.
At the high level, the primary system will be a repackaged Macintosh PowerBook (with active-matrix screen, possibly color). The keyboard in the rudder control grips and a pointing device will provide text entry and cursor control, and Digital Ocean’s Grouper (a wireless spread-spectrum AppleTalk link) will connect Microship computers to the one in my backpack. The second cockpit may contain a Mac as well to support the work of my companion.
Macintosh applications include Eudora for electronic mail, Word, ACT! database linked to GeoQuery, project planning tools, AutoCAD, MacDraw Pro, navigation and charting, language training, and demonstration software. This Mac, as on BEHEMOTH, will be my primary operating environment and link to the world.
Unlike BEHEMOTH, however, the Macintosh will not be essential to the operation of the low-level control system. On the bike, I did this to present a graphic user interface (HyperTalk layered atop FORTH), and although the Mac will still allow a pleasant work environment for all levels of the Microship system, it will not be necessary for basic operation. (Although it would reduce console real-estate by eliminating a second screen, using the Mac as the front-end for control negatively impacts the power budget, increases complexity, and introduces dangerous single-point failure potential in a critical survival area.) Instead, a low-power LCD screen will be managed by one of the micros, yielding a continuous display of navigation, safety, status, and environmental data:
- Latitude and longitude, waypoints, heading, & other nav data
- Air and water temperatures
- Radiation, salinity, pH, turbidity, depth, and trim
- Equipment bay pressure and temperature
- Barometric pressure, with trend data
- Time of day and stopwatch
- Battery status and estimated time-to-full or time-to-empty
- Power control map, local bus voltages, load & charge currents
- Drinking water level and desalinator status
- Security status and self-test
- Propulsion system performance and load-share
- Marine radar detected
- Communication system virtual front panel
- Processor and control system self-diagnostics
One of the design characteristics that made BEHEMOTH too complex was the presence of three separate equipment bays (console, RUMP, and trailer). Each imposed considerable overhead in terms of packaging, power distribution, control, cabling, and audio/serial networking. While the design is architecturally fascinating, the system is intimidating in scope and the documentation is a nightmare.
The Microship will be much simpler, with only one equipment bay and one straightforward network of microcontrollers. A single power distribution bus will suffice, and all I/O returns to the same header in the central pressurized hatch. Audio will be routed through one of the crosspoint boards developed for BEHEMOTH, and random serial communications will be handled likewise.
The low-level control network consists of about 8 processors, linked to a single hub that supports the display screen and can be addressed directly by the console keyboard. (We’re trying to choose the architecture now, with options including Echelon Neuron chips, multidrop, or the familiar serial crosspoint.) These little processors handle power management, propulsion control, environmental data collection, diagnostics, security, keyboard steering, audio networking, transceiver front-ends, navigation sensors, event scheduling, and other essential details.
Speaking of user interface, this project will again differ significantly from its predecessor. I may use a chord keyboard on the rudder controls as noted, though I’m considering a waterproof QWERTY keyboard, split in half and mounted on sliding armrests that control the rudder. This is faster and simpler to use, and if packaging constraints permit, would be preferable. Cursor control will no longer be an ultrasonic head mouse, since I have no intention of wearing a helmet on the water. I’m seeking a waterproof trackball, or may use a Measurement Systems joystick currently on hand.
As with BEHEMOTH, communication links to the outside world are critical — even more so, given the survival issues associated with being on the water. In addition to the EPIRB for life-threatening emergencies, the Microship will carry a full ham radio station, marine VHF, satellite email terminal, cellular phone with modem and fax, CB, security pager, and voice and data links to the backpacks of both crew. Additionally, new wireless mail services are severing the ties even further and will be explored as they become available.
The high-reliability Internet mail path is via the Qualcomm OmniTRACS terminal, a KU band link via the GSTAR satellite. This acquires and then tracks the geosynchronous bird even while the Microship is in motion, and extensive custom software (written for the BEHEMOTH project by Qualcomm) allows it to appear to the Mac’s mail system (Eudora) as a modem, passing messages to and from the net via a SPARC in San Diego. The system location-stamps outgoing messages with my latitude and longitude, which, although not as precise as the GPS navigation system, adds a level of comfort and security to open-water travel. A mapping program can display my location in real time (at the Computer Museum, Qualcomm, Scripps, and other places).
This is a slow mail path, however, useful primarily for high-priority short messages. Longer transfers, such as manuscript file transmissions, JPEG images, and the day’s routine mail (typically 60-80 messages), will take place through a high-speed modem attached to the cellular phone, new wireless email services, or hardwired connection at a host’s site.
The third data path is via ham radio — packet and AMTOR protocols. A widely supported network is in place, offering reasonably high reliability for non-business or emergency traffic, with AMTOR allowing worldwide email gateways to the Internet via the Icom HF transceiver and multimode TNC. (Business communication between backpack and boat will pass through wireless AppleTalk.) In addition to data communication, the Microship will be provided with extensive voice capability, with VHF marine radio as well as HF, VHF, and UHF amateur equipment. A major design goal here is to have 100% probability of being to reach someone somewhere, any time from anywhere. (The EPIRB should assure that… one flick of the switch in an emergency and the Microship will look like a 5-alarm fire to the Coast Guard.)
Finally, security is very much a communications issue — most responses to security violations (proximity, motion, shock, lat-long change without a password, hatch violation, and so on) involve some combination of paging me, transmitting help messages via satellite, or calling 911 via cellular phone and delivering an emergency voice message.
Power Generation And Management
With 664 watts of solar panels and some 300 watts of pedaling capacity split between two people, there is a significant resource-management issue here. Efficiency suggests running the array and thruster at 48 volts and then DC-DC converting that down to charge the main 12-volt system battery, but simplicity may rule. In any case, a significant task of one of the microcontrollers will be active management of power distribution, the percentage available for propulsion, and battery condition. Power distribution throughout the Microship will be modeled exactly after BEHEMOTH: A battery bus (overload protected) runs to all sites, with local software-controlled FETs and switching regulators dedicated to each load. Manual switching to high-reliability loads, like bilge pump and lights, will be provided to prevent a software crash from becoming a life-threatening situation, and a “JATO” mode will devote everything, including battery, to the thruster when I need to scoot out of the way of a freighter in the fog.
A continuous task on the power manager will be observation of battery status and prediction of time to full or empty based on observed performance. A map of the power distribution system can also be displayed to aid in diagnostics and task planning, with automatic load shedding to provide a graceful degradation of service as the battery level dips below normal levels.
In the past, my primary tool for capturing and publishing the essence of this nomadic experience has been text — writing stories which were transmitted electronically via the net. For this journey, I will add high-quality audio and video capability to allow pre- production of radio programs, publication of digitally transmitted still video frames, and capture of live video for later editing. All this has to be smoothly integrated with the Microship system — fumbling below deck for a camcorder is unacceptable in the heat of battle. An audio recorder will be remote-controllable, with stereo microphone near the console, and a miniature video camera will be mounted in a glass turret on deck. Beyond this, I don’t know the details… does anyone know of an RS-232 frame grabber to integrate my camcorder with the PowerBook?
As noted earlier, all audio is routed throughout the system via a software-controlled crosspoint matrix. This essentially allows anything to talk to anything — speech synthesizer, cellular phone, ham radio, MIDI system, entertainment audio, boom mic headset, marine radio, tape recorder, intercom to backpack, etc. Maximum generality is the key to the hardware design.
Safety And Survival Systems
Finally, there’s the matter of staying alive. This is much more of a challenge on the water than on the road, with one significant threat (drunk drivers) replaced by another (drunk powerboaters). Also, we have to deal with dehydration, drowning, hypothermia, cold shock, sharks, storms, surf landings, tankers in the dark, getting lost, hull damage, coral reefs, sickness, clapotis, and williwaws. No single technology can take care of all that, of course, but the Microship will be designed to maximize my chances of survival over the next few years. For visibility, strobe and bi-color marker lights will be built into the deck and mast, with LED taillights on the stern for land mode. The usual flare/smoke/dye kit will facilitate rescue operations, and electronically-launched rockets (wax-sealed fireworks?) may be mounted in a small bow fixture to alert a rapidly-closing vessel to my low-profile existence if they’re ignoring my radar reflection, flashing lights, and urgent shouts on Channel 16.
A reverse-osmosis desalinization system will provide drinking water, which not only keeps the engine hydrated but also serves as the coolant for the helmet heat exchanger used on the bike (Life Support Systems). This can pull approximately 75 watts of waste heat from my body, minimizing performance derating under conditions of elevated ambient temperature. Naturally, a full complement of wilderness camping gear, including cooking and medical supplies, will provide survival tools when I’m not in range of support facilities. This will be a more frequent need in the Microship than it was on BEHEMOTH, since only in the wild west have I encountered situations where essential services are often out of pedaling range.
So that’s the plan, and we have a place to work… on with the project!