Point Lonsdale Lighthouse Reserve's Nationally Important Maritime Rescue Heritage
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SECTION 6 POINT LONSDALE LIGHTHOUSE RESERVE’S NATIONALLY IMPORTANT MARITIME RESCUE HERITAGE Australian Historic Themes: 3. DEVELOPING LOCAL, REGIONAL AND NATIONAL ECONOMIES 3.16 Struggling with remoteness, hardship & failure 3.16.1 - Dealing with hazards and disasters 8. DEVELOPING AUSTRALIA’S CULTURAL LIFE 8.1 Organising recreation 8.1.4 - Enjoying the natural environment 8.2 Going to the beach 8.5 Forming associations 8.5.2 - Helping other people Pt Lonsdale Lighthouse Reserve – National Heritage Listing assessment Section 6 – Maritime Rescue - Page 1 This page is blank Pt Lonsdale Lighthouse Reserve – National Heritage Listing assessment Section 6 – Maritime Rescue - Page 2 SHIPPING MISHAPS AT PORT PHILLIP HEADS The danger of striking the often-uncharted rocks and reefs at The Heads was the ever-present cause of numerous shipwrecks. Many vessels tore open their hulls on the rocks at both Point Lonsdale and Point Nepean, and were either wrecked at those locations or foundered inside the Bay as water filled their hulls. Some ships sank as a result of collisions and some ran aground on sandbanks and were subsequently destroyed by storms. Vessels that could not be removed became shipwrecks (also known as “total constructive losses”), while successfully removed vessels were termed 'strandings'. The first documented shipwreck at The Heads occurred in 1840, when the cutter Prince Albert went ashore at Port Phillip Heads. Since then innumerable shipwrecks and strandings have occurred in the area, with the hulks of over 95 wrecks lying within 10 km of The Rip, both inside and outside the Bay. The proximity of the wrecks to the coastline, popular resorts and other essential services has led to a rich historical documentation of these events, along with an extensive collection of images of vessels ashore on shallow reefs at both sides of The Heads (Duncan 2006, p 215). Limited navigational services initially contributed to numerous strandings of vessels, particularly inside the bay where vessels often grounded on the constantly changing sandbanks and uncharted rocks. Historical research has identified well over 100 strandings or collisions. The first stranding in Port Phillip occurred in 1831 before the establishment of any permanent European settlement, when the cutter Lively washed ashore. The first stranding positively identified inside the study area occurred in 1839, when the cutter Superb went aground in the West Channel. (Duncan 2006, p.215) Port Philip Bay is known for its extremely wild and changeable weather patterns. There are many instances of fishing boat losses, along with their crew. Accurately predicting the weather was therefore an essential aspect of survival for bay users, especially the fishermen who frequented the dangerous shore areas in pursuit of catches. It is without doubt that The Rip is one of the most dangerous stretches of water in the world, accounting for many lives (and near mishaps) amongst the Queenscliff community, and the location of which required specialist knowledge of its intricacies and irregularities. The Rip was often spoken of in reverential terms by many mariners, “many mariners venturing through The Rip breathe a long sigh of relief when they are safely through its terrors” (Dod 1931, p.39). Many feared the crossing but were forced to accept it as an occupational hazard. One informant summed up the fishing community’s perception of The Rip: “Was The Rip dangerous? Christ yeah! Especially in a south-west wind and a big break … with the tide and a break coming behind you. A few boats got sunk there. I wasn’t too happy sometimes coming through I tell yeh!” (Duncan 2006). Fishermen therefore used alternate routes to mainstream traffic whenever the weather was boisterous. Smaller channels inaccessible to later vessels were used ashore of Lonsdale and Corsair Rocks in certain weather conditions to avoid the full effect of the tide or seas (Duncan 2006, p.203). GEOMORPHOLOGY INFLUENCE ON MARITIME ACTIVITY Influence of Tides, Currents and Weather – Essential knowledge Port Phillip Bay was formed when the Pleistocene coastal plain and tectonic depression was flooded to form a semi-encapsulated bay over 60 km wide at its extremities (Bird 1964:35). A horseshoe shaped underwater chasm up to 95 m deep straddles the entrance to Port Phillip Bay and is locally known as The Wall. The area was originally strewn with isolated uncharted pinnacles which often rose to within a few metres of the surface. These pinnacles were usually discovered by vessels striking them, and were often removed by blasting upon discovery of efforts to construct a safe channel through the Heads (Anderson 1997a: 7-8). A series of sand and mud banks form a delta from the former archaic Maribyrnong River mouth beginning approximately 5 km from The Rip and extending in a 5 km radius. The reduction in current velocity (and subsequent deposit of waterborne sediments) associated with tidal changes and channel narrowing at The Rip have produced an extensive sandbank delta. These banks are interspersed with up to six naturally occurring channels, cut by the former river course and tidal influences. The sediment in this area is highly dynamic, and, as shown in the following bathymetric chart of The Heads. Only two channels of sufficient Pt Lonsdale Lighthouse Reserve – National Heritage Listing assessment Section 6 – Maritime Rescue - Page 3 width, the West and South Channels, offer primary reliable courses for safe navigation. A third, Coles Channel, is navigable only through regular buoyage updates (Bird 1964, p.138). Bathymetry of Port Phillip Heads 2011 – Source www.ourcoast.org.au The Port Phillip Heads area is known for its often unpredictable conditions, and is considered extremely dangerous. The semi-enclosed topography of the Heads entrance constricted the tidal water flow either outside or inside the inlet (dependent on high or low tides), leading to a disparity of water levels of Port Phillip Bay and ocean outside (Bird 1964, p.9). The tidal influx is delayed by the narrow entrance, as only a restricted amount of water can flow through the inlet at any one time. The water levels inside Port Phillip Bay are therefore alternately higher or lower than the ocean sea level outside dependent on the nature of the tide. The water flow continues until equilibrium is achieved midway between high and low tides, when currents slow and reserve to produce the period known as “slack water”. However, slack water at The Heads actually occurs midway through the oceanic tidal stream, usually three hours after the tidal change and this is the opposite of the generally expected rule where slack water occurs concurrent with the change of tide (Anderson 1997, a7). Model of Tidal Influences at The Rip. HW = High Water, LW = Low Water (Anderson 1997a7) Furthermore, the water flow through the entrance to Port Phillip Bay is funneled through a 3.5 km wide entrance, locally known as The Rip, resulting in a severe tidal current of up to 7 knots. Tidal waters are known to hit the edge of The Wall (the edge of the underwater Rip chasm) and are redirected upwards towards the surface and along the wall, resulting in unpredictable eddies and whirlpools, and currents directed towards the shore (Yule 1876, p.271; Loney 1989, a1). The tidal flow also runs slightly athwart the entrance with great force, which was constricted for at least half of its width by shoal reefs and pinnacles on either side, and added to a confused sea and tidal rip. When sailing vessels attempted to navigate The Rip against a strong ebb tide, the vessels were often swept against the eastern peninsula, especially as the oceanic wind frequently eased off as the tidal water was reached, leaving the vessels unmanageable. The combination of the tides with a shallower approach reef outside the Heads and a very Pt Lonsdale Lighthouse Reserve – National Heritage Listing assessment Section 6 – Maritime Rescue - Page 4 deep chasm inside meant The Rip was often subject to high confused seas, especially in a south west gale (Yule 1876:305). Although ocean swells do not enter Port Phillip due to the narrowness of the entrance, wind generated waves are a constant danger within the Bay (Bird 1964, p.13-14). In ‘Wrecks on the Reef – A Guide to the Historic shipwrecks at Port Phillip Heads’, Heritage Victoria writes: “The Rip can, at times, take on the appearance of a giant washing machine, especially when the wind and the tide are in opposition. For example, with on onshore south-westerly wind and on outgoing ebb tide, the result is a stream of steep, choppy waves with no apparent pattern or order. These waves can reach huge proportions, sometimes breaking all the way across from Point Lonsdale to Point Nepean in south-westerly gales. Viewed from the air, the area of water affected by the Rip, even on a calm day, can be clearly seen as a confused choppy stream that can extend up to three kilometres out into Bass Strait. Whirlpools and eddy currents add to the confusion, and it is amazing that more soiling vessels were not wrecked as even today modern powered vessels can encounter serious difficulty in the Rip. Incidents involving recreational craft occur on a weekly basis. The incoming flood tide tends to flow in from the west over Lonsdale Reef, while the outgoing ebb tide flows out and around Point Nepean eastwards towards Cape Schank. A typical pattern, for example, is that a vessel attempting to enter or leave Port Phillip Bay on an ebb tide will end up in (or on) the Nepean Reef area, having been forced by the set of the current in thot direction. Between 1901 and 1987 the Port of Melbourne Authority (PMA), now known as the Victorian Channels Authority (VCA), undertook blasting operations to widen and deepen areas in the Rip to make the navigable entrance safer by removing pinnacles to make the channels a consistent depth” (Heritage Victoria 2006, p.7).