Unsure if standard equipment, but a common upgrade for 80s and 90s Sailboats. Mk 1 was the original offering from Harken. The earliest versions used roll pins to fasten the foils to each foil connector. These early versions are difficult to service and frequently destroyed when removed. This manual details the later versions of the Mk 1 which utilizes special screws (still available through Harken) to attach the foils to the foil connectors that Harken continued to use through their Mk. II & Mk. III units.
Mostly made from aluminum parts, easily serviceable and most parts still available either new or on the used market.
One failure mode which was improved on later models is that the foil connects to the drum via a simple clamp. This clamp can loosen over time and the foils can drop down and bind on the forestay. Later models used "teeth" in the torque tube to create a mechanical lock to avoid slippage.
Mostly made from aluminum parts, easily serviceable and most parts still available either new or on the used market.
One failure mode which was improved on later models is that the foil connects to the drum via a simple clamp. This clamp can loosen over time and the foils can drop down and bind on the forestay. Later models used "teeth" in the torque tube to create a mechanical lock to avoid slippage.