B) Firefly's Specifications


BUILDER/Year IW Varvet, Henån, Orust, Sweden, 1976
DESIGNER Sparkman & Stephens, New York, USA
MODEL IW-40, hull no. 6 (of 35), S&S Design #2186


Dimensions and tanks:

LENGTH 12.10 m 39.7 ft
BEAM 3.50 m 11.5 ft
DRAFT 2.10 m 7 ft
WATERLINE LENGTH (designed) 9.15m 30 ft
AIR DRAFT (bridge clearance incl. antenna) 17 m 56 ft
DISPLACEMENT (Designed/Actual?) 7.55/9 t 16600/20000 lbs
FUEL TANK (stainless steel) 90 l 24 USgl
WATER TANKS (stainless steel) 2 x 180 l 2 x 48 USgl



MAKE and MODEL: Volvo, MD21A (4 cyl. Diesel with mechanical gearbox RB)
CONSUMPTION 0.5 liter  per NM at 1800 RPM, 6 kts crusing speed

50 hp

TOTAL HOURS: about 3000
PROPELLER: Hasselfors Foldomatic 16 x 12; Replaced with KiwiProp in 2008
SHAFT 30 mm St/St; P-bracket with cutless bearing; stuffing box with "Drip-Free" packing


Note: This Volvo uses a Peugeot diesel engine block (by Indenor, France). The lube oil consumption is still low enough to not have to top up between 100 hrs oil changes. Many engine spares.


C) Equipment on Firefly


  • VHF: Icom IC-M45 with stainless steel whip antenna at masthead.
  • Log: Silva Nexus Sea-data (speed, log, water temp.)
  • Windspeed
  • Depth: Navman Depth 3100
  • GPS: Garmin 75 (+ spare)
  • Repeater display: Furuno RD-30 (2012)
  • Lapop computer with chart plotter; weatherfax.
  • Radar/plotter: Furuno 1722C Navnet in aft cabin or in cockpit; antenna mounted on front of mast (2002).
  • SSB/Ham radio: Icom IC 735 with autotuner to wire from transom to masthead
  • EPIRB: McMurdo 406 Mhz (2006)
  • Autopilot: AutoHelm 3000 (not used in heavy wind sailing)
  • Casette/stereo/CD with 4 speakers
  • TV: Grundig multistandard P 25-449/12
  • , digital converter & amplified antenna .
  • WIFI: long range 'Nanostation' receiver and onboard wired network.


  • Service batteries: 12 V, 430 Ah (2016).
  • Starting: 12 V, 70 Ah with parallel switch (2013).
  • Charging: 60 A alternator on main engine; 45 A/115 VAC auto charger; 15 A wind/towing generator.
  • Solar panels : 3x 100W semi-flexible, using Sunpower cells (22% efficiency), MPPT regulators (2013).
    Cambered and mounted over bimini. Covers all electrical needs in normal conditions.
  • Shore power: basic 30 A/115 VAC with 2 GFI duplex outlets, water heater and 45 A battery charger.
  • Generator: Portable Honda EU 1000i, 1000W, petrol.
  • DC panel with fuses, volt and amp meters.
  • Aquasignal St/St navlights on stern, combined at bow, on mast front; tricolor at masthead.
  • Deck light on mast front. Cockpit light under bimini.
  • 150 W 115 VAC inverter.
  • 6 x  12 V outlets.
  • Mostly LED lighting inside.
  • Portable spotlights: 12 V corded.
  • Fridge/freezer: Isotherm/DB35, air cooled (2011), consumption 14-25 Ah/day (depending on climate), box insulated with Aerogel (nano technology).
  • Fans: 2 in salon, others over aft bunks.


  • 3 CQRs: 25lb, 45lb, and 60lb.
  • Chain: 60m (180 ft) of 3/8" BBB;10m (30 ft) and 3m (15 ft) of 10mm.
  • Rodes: 75 m (240 ft) 16 mm nylon multiplait and 33 m (108 ft) 12 mm nylon 3-strand.
  • Windlass: Francis make, electric, vertical axis, with manual backup (1987).
  • 2 bow rollers (one main, one small)
  • The windlass is far enough back that the chain is stored under the aft end of the v-berth, putting the weight well aft and below the waterline.


Mainsail (laminated leach) Crusader, UK 1991 28 301
Genoa Elvström, DK 1976 60 646
Working jib 1 Elvström, DK 1976 34 366
Working jib 2 (biradial+UV strip) Crusader, UK 1991 35 377
Staysail (hanked on) McKillop, UK 1987 18 194
Storm jib Elvström, DK 1976 10 108


2 Spinnaker poles (full size and short one for jib)



  • 2 Enkes 32 2-speed (primaries) (Enkes size numbers are different from others, the 32's being much larger)
  • 2 Enkes 28 2-speed
  • 2 Lewmar 42 2-speed in front of cockpit with line clutches for halyards and mainsheet.
  • Lewmar 30 self-tail, Lewmar 16 2-speed and Lewmar 8 on the mast


  • Windvane: Aries "lift up" (1987)
  • Liferaft: Viking Rescue 4-man, cannister (2011)
  • Heater: Eberspracher (Espar) Airtronic D4 forced air; diesel; 4 speeds; 3 outlets (2001)
  • Bilge pumps: 2 manual Whale Gusher (in cockpit and salon bilge)

D) Description

  • Hull construction is solid fiberglass with foam stringers. Deck and cabin top are foam core sandwich with teak planking. (For hardware, winches, mast partners, etc., the foam core was substituted with aluminium plate, making it very strong and stiff.). Topsides are painted (new 2005) with white Awlgrip, a blue cove stripe and water line . There is a slight tumblehome. A very strong and safe construction. There is no flex in the deck anywhere.
  • Keel is 4.06 tons cast lead with stainless keel bolts, and a stainless V-shaped "shoe" on the bottom edge.
  • The toerail , mast, boom and spinnaker pole are clear anodised aluminium (on later IW 40's they are black).
  • The rig is a single spreader, clear anodised aluminium extrusion by Selden (E-section 237/162), with single lower shrouds, baby stay, inner forestay and running backstays. The backstay has a David Carne hydraulic tensioner and the headstay a Hood Seafurl 5 (2002, lifetime warranty). The main standing rigging is 10mm 1x19 wire (headstay 2002, lowers 2011, inner, runners and baby 7 and 8mm 1987). With the addition of the inner forestay, running backstays and intermediate shrouds (1987) we feel the rig could withstand loosing any one stay.
  • There are 2 Goiot hatches (new Plexiglas 2001), and 3 stainless steel framed clear windows on each side of the house. (On other IW's, the windows appear as one long black band on each side).
  • There are 2 sliding hatches: the original entrance from the bridge deck down into the main saloon, plus the aft entrance directly from the cockpit into the aft cabin. (The aft entrance, added after the building, is probably unique to this and a couple of other IW 40).
  • The wheel steering is by chain and cable to a quadrant, with 3.5 turns hard over to hard over. The rudder has a full skeg with lower bronze on st/st bearing.
  • The deck hardware (turning blocks, sheet tracks, etc.) is Lewmar, of a size mostly found on larger boats.
  • The cockpit has teak seats, floor and coamings. There is a rope locker to stb. and a self draining propane locker to port, with two 5kg tanks, solenoid valve and pressure gauge for leak testing (the pipe to the stove is a single copper tube with no joints other than the hose connections at either end). New bimini sunshade 2012.
  • On the stern there are 2 liferings (one with a long floating line, one with a backstay mounted lighted man overboard pole). There is also one throwable rescue line package.
  • The stainless steel hardware (pushpit, pullpit, stanchions, steering wheel and entrance side bars) is of premium Norwegian quality that does not rust or pit.
  • The foredeck has a locker for fenders, dinghy fuel, etc.
  • The fiberglass, clinker style dinghy fits on deck below the boom (upside down or top side up) and covers the forward entrance hatch. The 2.5hp outboard engine fits on a pushpit bracket. This is a good sturdy rowing boat.
  • The interior is finished in teak faced marine plywood, with solid teak trim. Where there are curves, the trim is laminated teak (door frames, seat edges, galley and head counter edge, crash bar in front of stove, etc.). The floors are teak and holy faced plywood. The ceiling panels are off-white vinyl with varnished teak battens
  • The interior layout is different from the standard one (see the layout plan). The aft cabin is similar, but with the addition of the cockpit entrance, and a larger stb. side bunk (but no door forward to stb.).The fuel tank is under the aft section of the stb. bunk; it has a drain valve at the bottom for water stripping. Moving forward, to port is a chart table, then galley, with two burner Upo gimbaled oven/stove, twin sinks with pressure hot and cold (also a foot pump) water (new pump and water heater 2012), a salt water faucet (foot pump) and a filtered drinking water spigot. There are two large pull out vegetable bins, cupboards and other food storage. The headroom in the center has been increased from the original by lowering the floor about 8cm. To starboard is a U-shaped settee, with a table that can slide sideways to facilitate getting in and out. The table also lowers to make a large bunk. In the center is the engine and fridge box, below the bridge deck entrance hatch. The fridge can easily be removed for total access to the aft part of the engine. The top, front, sides and part of the aft of the engine box can also be removed for access. Forward is the other part of the saloon, with port and stb. settees/bunks, book shelves, and closets. The 2 water tanks under the settee/bunks have inspection hatches for easy cleaning. There is a small table on the mast which can be raised to the ceiling, out of the way. Forward to port is the head (Blake Lavac), washbasin and a shower with electric sump pump (thermostatic water temperature control; 'hot water valve to tank' for quick hot water without waste). To stb. are two closets, and in front, a short V-berth, with storage underneath, including the chain locker (which drains into the shower pan).
Page 1 Home
A) Summary
Page 2 B) Specifications
C) Equipment
D) Description (here)
Page 4 E) Layout & Photos
Page 5 F) Voyages
G) History

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