Historical Significance or Value
The historical significance of Cape Brett Lighthouse Station has two aspects, its significance at the time it was built, and perhaps even more importantly its survival to the present in an almost completely intact state.
Cape Brett Lighthouse was an important component of the second phase of New Zealand lighthouse building. Once the initial chain of coastal lights had been installed, and as patterns of oceanic trade changed, the need for lights to guide ships approaching from the northeast, from the United Kingdom via Panama and from the United States, became important. As one of only nine first order lighthouses in New Zealand, its size, prominent siting and long range visibility made it a significant part of the lighthouse protection of the New Zealand coast. It is notable that it was the last first order lighthouse to be installed, significantly later than the others, and was the only first order lighthouse installed in New Zealand in the twentieth century.
The lighthouse at Cape Brett was seen as needing to be large and substantial. Because it was a twentieth century first order light, Cape Brett was the first lighthouse in New Zealand to use a mercury bath to support the rotating optic. This was a significant innovation, enabling the very large optic to be readily managed, providing a more stable platform for the rotation and thus a more reliable signal than the rollers and bearings of the earlier first order lights.
Cape Brett lighthouse is remarkable in that it is virtually complete as an abandoned installation, and could be returned to a fully operational state without very much restoration, as conservation architects Salmond Reed noted in 2000. Due to the robust construction of both the lighthouse structure and the operating mechanism, the entire complex has survived in excellent condition, and without parts being removed as has happened elsewhere. Cape Brett Lighthouse is unique in New Zealand as the only lighthouse to have survived in place with its original equipment substantially intact. It thus presents a window in time, showing the complete working of a lighthouse through the whole range of lighthouse operation in New Zealand. Uniquely, it still has its clockwork rotating mechanism, the driving chains and weights for the clockwork, the air and oil fuel cylinders for incandescent kerosene operation, the electric bulb changing mechanism for electrical operation, the mercury bath 'frictionless' floating bearings, and the magnificent first order prismatic glass and brass Fresnel rotating group flashing lenses. It has NZ Lighthouse Service standard issue clockwork, mercury bath and incandescent kerosene spare parts still stored in the spare part cupboard.
All of this operating mechanism remains intact, and importantly, still in the context of its use. Elsewhere some of these elements of lighthouses do survive, but they have been removed to museums or relocated as the lighthouses have been moved. At Cape Brett, very little has changed. The context also includes the lighthouse settlement. Even with the removal of many of the buildings, the layout of the whole site and the building remains make very clear the context in which the lighthouse stood and still stands, as part of a whole lighthouse station landscape.
Aesthetic Significance or Value:
Like many New Zealand lighthouses, Cape Brett Lighthouse Station has aesthetic value because of its rugged, isolated and often bleak maritime location, and the sometimes idealised romantic associations of the harshness of life in such an isolated place. Cape Brett Lighthouse Station is a significant and prominent element in the coastal landscape of the southern headland of the Bay of Islands, while at the same time appearing as a small and frail human element in powerful natural surroundings. The place has a remarkable sense of isolation and remote beauty. Ironically, because of its proximity to Piercy Island and the cavern that runs though it, this remoteness and rugged beauty is easily accessible to a substantial public audience, which makes visits on the popular Bay of Islands tourist attraction of a boat trip to 'The Hole in the Rock', one of the most visited places in Northland.
Archaeological Significance or Value:
Cape Brett Lighthouse Station was a large lighthouse establishment by New Zealand standards, with three resident keepers throughout its manned operation. Apart from the tower itself and the surviving Assistant Keeper's house, all the other buildings necessary to the functioning of a lighthouse establishment were demolished and removed. Their foundations remain intact, as do the infrastructural elements such as the landing, parts of the gantry and crane, the tramway and the engine houses. Because there has been very little subsequent development of the site (the installation of the modern beacon being the principal exception) the whole lighthouse station site remains almost completely intact. The rich photographic and oral history records of the occupation of the site mean that a great deal is known about its functioning, but the potential to test and expand that understanding through archaeological investigation is very real indeed. The site has been recorded in the NZ Archaeological Site Recording Scheme as Q05/1276.
Technological Significance or Value:
Lighthouses worldwide contained a number of elements of considerable technological significance, and because of the intact state of Cape Brett lighthouse, these technological innovations remain to provide evidence of those advances. The Fresnel lens represented a major advance in optics and illumination, considerably improving safety at sea, as well as providing stimulus to advances in optics and lens manufacture. The development of the mercury bath provided an elegant solution to the problem of supporting and rotating a substantial weight in a confined space. Clockwork has become a much less common technology in recent years, so that the precise and accurate clockwork of the nineteenth and early twentieth century machinery in the lighthouse represents an increasingly rare example of technology that had very great significance worldwide.
Cape Brett lighthouse is unique in New Zealand as a place that presents these technological innovations complete and in their original setting.
Social Significance or Value:
Lighthouse keepers and their families represent a distinct community within New Zealand society. Keepers moved from one location to another, but also developed quite intense and not always easy relationships with other personnel at the lighthouse where they were based. From the many primary resources, both official and private, it has been possible to develop a detailed picture of the way of life of the keepers at Cape Brett and their families, and this material is used by the Department of Conservation to interpret the history of the site to visitors, both physically and virtually through a website. Because so much physical evidence of the lighthouse settlement remains, it is possible for visitors to gain a good appreciation of what life was like, so that the buildings and other physical remains can be brought to life though the stories of the people who once lived and worked there. Although lighthouse people represented only a very proportion of the New Zealand population, public fascination with their lives and work means that a place like Cape Brett that enables a better understanding of that life has a social significance well beyond the number of people actually involved.
(a) The extent to which the place reflects important or representative aspects of New Zealand history:
The development of the lighthouse network around New Zealand's coasts was a very significant element in the development of communications, trade and economic development in New Zealand. Cape Brett lighthouse was a significant component of the second phase of the development, reflecting changing patterns of trade and shipping routes in the twentieth century. As the only first order lighthouse built in the twentieth century in New Zealand, Cape Brett occupies a prominent place in that history.
(g) The technical accomplishment or value, or design of the place:
Cape Brett is a place unique in New Zealand in containing in their original context a number of technological innovations that were important both in New Zealand and worldwide. The optics of the Fresnel lens were a very significant innovation in the early nineteenth century, developed and improved by several major European engineering companies, which provided the equipment for the Cape Brett Lighthouse. The mercury bath provided an elegant solution to the problem of supporting and rotating a substantial weight in a confined space. The engineering accomplishments of the Thames firm of Judd Engineering also represents New Zealand's excellence at that time in heavy manufacturing.
(j) The importance of identifying rare types of historic places:
Cape Brett lighthouse station is unique in that it is the only lighthouse in New Zealand to remain intact in an almost operational state, with all the equipment used throughout its operational life still present, and in its original context.
Summary of Significance or Values:
This place was assessed against, and found it to qualify under the following criteria: a, g and j.
It is considered that this place qualifies as a Category I historic place.
Cape Brett Lighthouse is remarkable in that it is virtually complete as an abandoned installation, and could be returned to a fully operational state without very much restoration. Cape Brett Lighthouse is unique in New Zealand as the only lighthouse to have survived in place with its original equipment substantially intact. It shows the complete working of a lighthouse through the whole range of lighthouse operation in New Zealand. All of its operating mechanism is intact and remains in the context of its use. This context also includes the lighthouse settlement. Even with the removal of many of the buildings, the layout of the site and the building remains make very clear the context in which the lighthouse stood and still stands, as part of a whole lighthouse station landscape.
Early New Zealand Lighthouses:
The New Zealand coast experienced shipwrecks from the earliest period of European settlement. The Australian schooner Parramatta was the first vessel to be actually wrecked on the coast of New Zealand, when it was driven ashore in a gale near Cape Brett In 1808. (New Zealand's 'first' shipwreck, the Endeavour was deliberately hauled onshore in Dusky Sound in 1795 because of her deteriorated condition) .
The history of lit navigational aids in New Zealand began in the early 1830s, when a beacon was erected at Maketu in the Bay of Plenty. In the early years of the colony, inbound vessels frequently had difficulty in identifying ports due to a lack of navigational aids, and shipwrecks were common. During the 1850s and early 1860s, permanent lighthouses were erected by the Wellington and Nelson Provincial Councils, including an imported cast iron structure at Pencarrow in 1858-59 - the earliest permanent lighthouse in New Zealand. In 1861, a countrywide approach was outlined to provide the coast with thirteen structures, together with five lights at other harbour entrances. This plan was adopted after responsibility for navigational aids was given to a national body, the newly-appointed Chief Marine Board (later the Marine Board of New Zealand), in 1862. The Board completed the construction of several new lighthouses, including the earliest stone examples, before becoming the Marine Department in 1866.
James Balfour, who had designed the stone lighthouse at Dog Island, was appointed Marine Engineer for the new department. He set about reforming the lighthouse service following the Scottish model with which he was familiar. In the interests of speed and efficiency, Balfour adopted a policy of erecting lighthouses in timber wherever possible. After his death in 1869, this policy was continued through the 1870s and into the early 1880s by John Blackett and Captain Robert Johnson. Blackett was responsible for engineering and technical duties, while Johnson - who had instigated the 1861 plan to provide national lighthouse coverage - was head of the department. Under their stewardship, the 1870s proved to be the peak decade of lighthouse construction in New Zealand, and by 1879 there were some 25 lighthouses guiding vessels around the waters surrounding New Zealand. A further six were erected in the early 1880s before economic depression contributed to a decline in construction activity.
Changing international and coastal shipping routes made the provision of additional lights on the northern North Island east coast a high priority. Cuvier Island Light was lit in 1889, East Cape Light in 1900, Cape Brett in 1910 and an automatic light on Coppermine Island in the Hen and Chicken Islands in 1913, completing the chain of lights along the northeast coast of the country.
Once the major period of lighthouse construction was concluded, the Marine Department turned to the day to day operation and management of the lighthouse system. The Department underwent no major changes until 1972 when it was absorbed by the Ministry of Transport, later becoming part of the Ministry's Nautical Branch. In 1990 it became a separate Crown entity - the Maritime Safety Authority - before being renamed Maritime New Zealand in 2005.
Cape Brett was named by James Cook in November 1769 for Sir Piercy Brett, who was a Lord of the Admiralty 1766 - 1770. To Maori, to Ngapuhi and especially the local hapu Patu Keha and Ngati Kuta, it is Rakaumangamanga, named by Kupe and one of the Pou of Te Wharetapu o Ngapuhi. 'This saying is well known among Ngapuhi. It figuratively describes the territory of Ngapuhi as a house for which the mountains are the supports...they stand as symbols of the mana of Ngapuhi. Ngapuhi lands spread there beneath these mountains, posts of the house of Ngapuhi, the multitude of Ngapuhi are nurtured here.'
Rakaumangamanga, meaning literally 'multi-branched tree', is the name of the high point on the peninsula, to the south of the lighthouse, but can be seen as applying to the whole headland. Tiheru or The Dog Island to the north of the Cape is said in some accounts to be the bailer of the Mataatua canoe, lost on the voyage north to its final resting place in Takou Bay.
Cape Brett Lighthouse:
The first discussion of the need for a lighthouse at Cape Brett was in 1874, when Mr J.R. Williams hosted a public meeting in Russell to relay the recent proceedings of Parliament. During this meeting the floor was opened to questions and one gentleman enquired as to a lighthouse for Cape Brett. Mr Williams replied that he ‘would be very glad to see a lighthouse on the Cape, but did not think it would be granted by the government'. In 1896 the Nautical Advisor proposed a light in this location - though the suggestion was passed over in favour of other lights. Thirty-three years later the idea was again mooted by the Marine Engineer to the Secretary of the Marine Department Marine Engineer in a 1907 report.
The North Cape, or Cape Brett on the Southern side of the Bay of Islands appears to be the best place where a light is most urgently required as there is now no light between Cape Maria Van Diemen and Moko Hinau.
The report went on to point out that a light at Cape Brett was the most wanted light in the Colony. Consultation with the Shipmasters' Association put forward the Cavalli Islands, north of Cape Brett and the Poor Knights Islands to the south, as alternative locations. In December 1907 the Cape Brett Peninsula was chosen as the most advantageous location for a light for shipping purposes following investigations by Captain Bollons of the GSS Hinemoa, Mr J.A. Wilson, Auckland District Engineer, and the marine engineer of the time. Orders were soon put in for the necessary building materials and lighthouse parts, most of which had to be come from England.
Construction on the settlement started in 1909 after surveying on the newly acquired land at the tip of the Peninsula. The light was first lit on the evening of 21 February 1910 and kept a watch on this coast until 5 October 1978. The adjacent automatic beacon was first exhibited the following night.
The Cape Brett Lighthouse was designed by the Marine Department's specialist lighthouse designer David Scott. He was officially employed as a ‘lighthouse artificer' and Cape Brett was his final lighthouse before retirement. The light was designed by Messrs Stevenson, Civil Engineers of Edinburgh, and made by Chance Brothers and Co. Ltd, Birmingham and James Milne and Son Ltd, Edinburgh.
The Marine Department called for tenders for the construction of the tower on 1 December 1908, with tenders closing on 18 December 1908. The successful tenderer was Messrs Chas Judd and Co. Ltd, an iron and brass foundry in Thames. The Public Works Department officially accepted the contract for £930 18s 9d (approximately equivalent to NZ$135,000 today) on 8 January 1909 and it was signed by the brothers James Charles and William Henry Judd. The tower plans for construction were signed by the brothers on the day the bond of £100 was lodged. The completion date on the contract was 8 May 1909.
The tower was constructed and assembled at the Judd foundry yard in Thames to make sure that all necessary parts were there, then dismantled for re-assembly at the Cape. The Cape Brett tower was one of four cast by the company, the others being the towers at Cape Campbell (1870), East Cape (1900) and Kahurangi Point (1903).
For its first 45 years of operation Cape Brett Lighthouse was powered by incandescent kerosene burnt under pressure in a mantle within the Fresnel lens. In 1955, the lighthouse was converted to electricity provided by diesel generator. In 1967, after a significant engineering operation including the use of a helicopter to install the pylons, the lighthouse was connected to the national electricity grid.
In the 1970s, like other New Zealand lighthouses, Cape Brett Lighthouse went through the change to install automatic equipment and remove the personnel from the site. In 1978 the keepers and their families were withdrawn as a fully automated beacon was installed beside the lighthouse tower. On 5 October 1978 the Cape Brett Lighthouse tower was lit for the last time, and on 6 October the adjacent electronic beacon was illuminated for first time. Because the lighthouse station and its buildings were no longer required, the buildings were sold and removed. The exception was the Assistant Keeper's former house, which was opened in 1995 as Department of Conservation hut for the use of trampers and other visitors. The former Lighthouse Reserve became a Recreation Reserve, with the exception of the small piece of land that contained the new electronic beacon and the former lighthouse tower.
In 2000, the then Maritime Safety Authority (now Maritime NZ) advised NZHPT of its intention to demolish Cape Brett Lighthouse, because of concern at the cost of its upkeep now that it was no longer required, and because of the perceived hazard of the mercury bath. The Northland office of NZHPT saw the demolition of this significant historic building as being inappropriate, and after negotiation it was agreed that the Lighthouse would be passed to the Department of Conservation, which already administered the surrounding land. Maintenance had been deferred for some years by MSA because it no longer had a use for the lighthouse. In 2007 the Department of Conservation painted the exterior of the by then very rusted tower.
Government Life Insurance Department Postage Stamps:
The Government Life Insurance Department (now Tower Corporation) was the only government department, apart from the Post Office, allowed to use its own postage stamps. Special Government Life Insurance Office stamps were first issued in 1891, a lighthouse being incorporated in the original design. In 1947 new stamps were issued, designed by James Berry. They featured lighthouses around the New Zealand coast and the Eddystone lighthouse on the Cornish coast, as a tribute to the British heritage, in a series of eight stamps in denominations from a halfpenny to one shilling. The one shilling stamp featured Cape Brett Lighthouse.
Lighthouse keepers and their families represent a distinct community within New Zealand society. Keepers moved from one location to another, but also developed quite intense and not always easy relationships with other personnel at the lighthouse where they were based. Quite a number of lighthouse keepers and their families have written books about their experiences in the New Zealand Lighthouse Service, and these books have found a ready audience based on a public appreciation of what is seen as a rather romantic as well as perhaps eccentric way of life.
From the 1950s the Marine Department purposely hired married men for the keeper roles, presumably to reduce the loneliness and to encourage a sense of community. From the 1960s there was a shift to hire keepers with more applicable trade skills and an inventive mind, especially relating to diesel electric equipment. This reflected the shift in technology used in lighthouses and the need to have someone onsite if the light stopped working. Keepers were also assessed for even temperament in an emergency, good social skills and pleasant manner. These aspects were apparently assessed by a department psychologist for whom there was a long wait for appointments.
During the first half of Cape Brett's functional life the keepers worked in a three shift cycle every night, starting an hour before sunset and ending at sunrise. The first keeper would light the lamp and would stay in the light to maintain the gas pressure - by hand pumping - in the kerosene lamp. He would also spend 15 minutes of every hour winding the weights. The last keeper would be assigned the job of trimming the lamps, cleaning the lenses and drawing the curtain to prevent sun damage to the lens. The routine post-electrification involved the keepers spending an hour each morning and evening tending to the light. The routine consisted of a 20 minute walk up to the light, 20 minutes for turning the light on or off and then the 20 minute walk down from the light. The hour would start 20 minutes before dusk and 20 minutes after daybreak.
Much of the rest of the keepers' time on the stations was split between paperwork, maintenance and life-support activities. The paperwork was a necessity and related to every aspect of the station's running and it would appear that the Marine Department eventually managed to develop a form to suit every occasion. Maintenance consisted of keeping the tower, houses and auxiliary buildings up to standard. The machinery had to be maintained and strict records were kept on all parts and when they needed to be replaced. Other tasks included maintaining and renewing fences, repainting buildings and tower when necessary, laying concrete, cutting grass and chimney sweeping. The life-support activities consisted of the ordering, unloading and distribution of supplies, tending to the horse, cows, chickens, milking, butchering any animals for fresh meat, fishing, tending to the garden and harvesting fresh vegetables. Most of these activities also had to be worked into the daily routine for the keepers, possibly with help from their wives if they had time.
The life of a keeper was extremely busy especially for the principal keeper who had to act as Justice of the Peace, chairman of the school committee, fisherman, butcher, gardener, farmer, weatherman, mechanic and carpenter. The assistant keepers took the role of postmaster more than the principal keepers, with the rest of their time taken up with specially assigned tasks; at Cape Brett it was shooting goats.
In her research for the Department of Conservation, Christen McAlpine used a range of official and private sources to develop a detailed picture of the way of life of the keepers at Cape Brett and their families, and this material is used by the Department to interpret the history of the site to visitors, both physically and virtually through a website. Because so much physical evidence of the lighthouse settlement remains, it is possible for visitors to gain a good appreciation of what life was like, so that the buildings and other physical remains can be brought to life though the stories of the people who once lived and worked there.
Cape Brett Lighthouse was designed by David Scott, the Marine Department's Lighthouse Artificer. Scott was involved in the design and construction of a number of New Zealand lighthouses for the Marine Department. Cape Brett was his final design before his retirement.
The iron tower of the Cape Brett Lighthouse was constructed at the Thames Iron Works of Charles Judd; the contract was signed by Charles Judd's sons James Charles Judd and William Henry Judd. Charles Judd came to New Zealand in 1859, and worked originally in Auckland. In 1869 he established the Thames Iron Works on what became a substantial site in the centre of Thames. He smelted the first iron on the Thames Goldfield. The foundry catered for the mining and sawmilling industries, eventually supplying equipment to all parts of New Zealand but especially the Auckland Province. Judd's made fire plug boxes, sewerage manhole covers, cesspit grates, iron pipes and gas lamp posts. The Thames Iron Works made the cast iron towers for the lighthouses at Kahurangi Point (1903), Cape Campbell (1905), East Island (1906) and Cape Brett (1910).
The light was designed and part fabricated by Messrs Stevenson, Civil Engineers of Edinburgh. The optics were made by Chance Brothers and Co. Ltd, Birmingham, and the lantern, parapet, carriage and mercury trough and clockwork rotating mechanism by James Milne and Sons Ltd, Edinburgh .
Robert Stevenson (1772 - 1850) was a Scottish engineer and lighthouse designer, responsible for building fifteen lighthouses between 1811 and 1833. Through his sons Alan (1807 - 1865), David (1815 - 1886), and Thomas (1818 - 1887) and grandsons David A (1854 - 1938) and Charles Stevenson (1855 - 1950), he established a dynasty of lighthouse engineers. The novelist and poet Robert Louis Stevenson was a grandson who did not follow the family profession.
Robert Lucas Chance bought the blown window glass works of the British Crown Glass Company in Spon Lane, Birmingham in 1824. The company's future was guaranteed in 1832 by investment from William and George Chance who were successful Birmingham iron merchants. They became partners in the business, now called Chance Brothers and Company. In 1832, Chance Brothers became the first British glassworks to adopt the cylinder method to produce sheet glass, and overtook all rivals to become the largest British manufacturer of window and plate glass, and optical glasses.
Chance Brothers also became a major lighthouse engineering company, producing optical components, machinery, and other equipment for lighthouses around the world. James Timmins Chance pioneered placing lighthouse lamps inside a cage surrounded by Fresnel lenses so as to increase the available light output; these optics revolutionised lighthouse design. Another important innovation from Chance Brothers was the introduction of rotating optics, allowing adjacent lighthouses to be distinguished from each other by the number of times per revolution that the light flashes.
Chance Brothers' other projects included the glazing of the Crystal Palace and the Houses of Parliament, including the opal glass for the four faces of the Westminster Clock Tower which houses Big Ben. The ornamental windows for the United States White House were also made there. Other products included stained glass windows, ornamental lamp shades, microscope glass slides, painted glassware, glass tubing and specialist types of glass.
Pilkington acquired a 50% shareholding in Chance in 1945, then assumed full control of Chance Brothers by the end of 1952. The production of flat glass ceased at Smethwick in 1976. The remainder of the works closed in 1981, ending over 150 years of glass production at Smethwick.
Milne was an Edinburgh brass founder who commenced business in 1824. By 1894, the Company was James Milne and Sons Ltd., and it was under that name it provided equipment for Cape Brett, as well as many other lighthouses worldwide. For example at Copinsay Lighthouse built in the Orkneys in 1915, Milne and Sons built the lantern, parapet, revolving machine, carriage and mercury trough. It seems likely they were responsible for the same elements at Cape Brett.
Cape Brett Lighthouse:
The Cape Brett Lighthouse has a 15.3 metre high cast iron tower, constructed in five tiers with the lantern and dome above. A small square entrance room outside the tower gives entry into the circular ground floor room, with a curving iron ladder giving access to the floor above. The first floor also has a similar ladder giving access to the light room, in which is housed the machinery to rotate the light and the mercury bath supporting the light itself, which projects up into the lantern with its windows to the sea. An iron ladder from the first floor room gives access via an exterior door to the gallery that runs around the tower. From the gallery, external vertical ladders give access to the exterior of the lantern, to the copper dome and ultimately to the spherical vent with its lightning rod.
The ground and first floor rooms have a square open hatch in the centre, guarded by a wooden rail, to allow the weights driving the clockwork rotational mechanism to descend, at their fullest extent into the cavity below the ground floor.
The lantern contains a first order light with a Fresnel lens containing two 'bulls-eyes' to create the two flashes. The light source is enclosed within the revolving bronze frame that holds the glass bulls-eyes and other lens elements. First order lenses were the largest type, designed for important coastal sites. Lenses ranged down in size to the sixth order, the smallest, which was designed for small harbours and rivers. Because the two bulls-eyes revolved around the light source (kerosene and later electric lamps), the light emitted a flashing white light, 2 flashes in quick succession every 30 seconds. Situated 155 metres above sea level, it could be seen for 49 kilometres.
In 1819, the French Government commissioned physicist Augustin Fresnel to develop an improved lighting system for French lighthouses. Fresnel explored ways that glass lenses could be used to concentrate the light source. Since a single lens of sufficient strength would be too large to be practical, Fresnel used multiple prismatic lenses surrounding the light source to capture the light rays emitted from a single light source and direct them into a narrow horizontal beam.
In its simplest form, Fresnel's design was a barrel-shaped array of lenses encircling the light source. In the area immediately horizontal to the light source, dioptric lenses magnified and concentrated the visible light as it passed directly though them. At the same time, above and below the light source, multiple catadioptric prisms mounted around the periphery of the barrel each collected and intensified the light and redirected it in the same plane as the dioptric lenses. Light output was increased dramatically from the old reflector systems, with as much as eighty percent of the light transmitted over thirty kilometres out to sea.
In the centre of many Fresnel lenses there are circular 'bulls-eye' panels, which bend the light into a circular beam. By rotating the optic array, different flash patterns could be obtained by placing one or more 'bulls-eye' panels around the circumference of the array, and varying the speed of the rotation. This provided each lighthouse with its own signature flash rate.
Because Fresnel's design involved modular construction, a Fresnel lens could be built in one location, disassembled and easily shipped in multiple small sections, making transportation and re-assembly in the tight confines of a lantern room significantly easier than would have been the case with an optic made up of a few large glass elements.
Fresnel's design was so revolutionary that it was immediately adopted world-wide as the standard lighthouse lens, a pre-eminence that it maintained well into the twentieth century. This type of optic array became known as the 'Fresnel' lens. Before his death in 1828, Fresnel began to collaborate with the Scottish engineering firm of D and T Stevenson, who took the basic Fresnel concept and further developed it, working in collaboration with Chance Brothers of Birmingham. As noted above, Stevensons designed the light for Cape Brett and Chance Brothers built the optics, with James Milne and Son of Birmingham constructing the clockwork winding gear that supports it, the lantern, parapet, revolving machine, carriage and mercury trough.
Fresnel's lighthouse lenses are divided into six orders based on their focal length. The order of a Fresnel lens is approximately the Dioptre or optical power of the lens, which is the reciprocal of the focal length of the lens in metres. A Fresnel lens with a focal length of 50 centimetres or 0.5 metres is classified as a second order lens. The largest (first order) lens has a focal length of 920 millimetres and an optical area 2590 millimetres high. The complete assembly of a first order lens is about 3.7 metres tall and 1.8 metres wide.
Cape Brett is a first order light, the only first order light to have been installed in the twentieth century in New Zealand. New Zealand Lighthouses that had first order lights were Dog Island (1865), Nugget Point (1870), Centre Island (1878), Cape Reinga (originally at Cape Maria Van Diemen 1879), Puysegur (1879), Mokohinau (1883), Cuvier (1889), Stephens Island (1894) and Cape Brett (1910). With the exception of Nugget Point and Cape Brett, these optics have been removed; at Nugget Point the optic is stored in the lighthouse tower. Puysegur was destroyed in a fire in the 1940s.
Cape Brett Lighthouse was the first in New Zealand to have a mercury float or mercury bath installed to support the Fresnel lens. Earlier methods had involved rollers and ball bearings.
To rotate a very heavy glass optic apparatus, a mechanism was needed that offered the smallest resistance while taking the least amount of space. A circular trough forms a container into which is fitted the frame of the optical apparatus. The optic carrying vessel is shaped like a hollow cylinder which fits inside the slightly larger circular trough. With no liquid, the optic would just sit on the bottom of the bath, and its rotation would be impossible.
When the trough is flooded with liquid the liquid starts to buoy the vessel. The requirement is to place the right amount of liquid in the trough to give it enough buoyancy to float the vessel. This critical volume could be quite large depending on the liquid medium.
A first order lens with its support and other associated parts weighs over 4300 kilograms. If water was used, the volume of the basin required to float the apparatus would require a circular trough 3.3 metres deep. Not only is such a deep float hard to accommodate in a confined space of a lighthouse, but from an engineering point of view, such a mechanism would be impossible to manage because of the instability of the water surface.
Despite its poisonous nature, mercury was found to be the best medium. Not only is it not corrosive to cast iron, it is also non-flammable, being almost inert to any chemical reaction at normal temperature. Since mercury is 13.6 times heavier than water, the same 4.3 tonne optic requires a trough only 25 centimetres deep. The density of the mercury creates a very stable surface for the optic to float on.
The mercury bath provided an elegant solution to the problem of rotating heavy optics quickly without expending energy on overcoming the friction. The whole mechanism could be easily turned with a gentle push. The mercury float provided increased rotational speed of the mechanism, near-frictionless rotation, was able to take more weight than the roller and ball bearing method, and offered less wear and tear, giving a longer lifespan. At the levels of exposure they would have experienced, it is unlikely that the keepers suffered any mercury poisoning.
Cape Brett was the first lighthouse in New Zealand to use a mercury bath. Several other existing lights, such as Dog Island (first order, built 1865) and Castle Point (second order, built 1913) were converted to use a mercury bath, although these were later re-converted to a slew ring in the 1970s when mercury became recognised as a hazard. Cape Brett is now the only lighthouse in New Zealand with a complete, operational mercury bath. The one at Dog Island is still intact but the mercury has been removed. Akaroa Lighthouse is another relatively intact lighthouse, with its second order Fresnel lens and roller mounted rotational equipment intact. However, while its operation is capable of being demonstrated to visitors, its relocation to its inner harbour site has completely removed it from its historic context.
Other lighthouse station buildings:
Cape Brett Lighthouse Station was staffed by a Principal Keeper and two assistant keepers. A number of buildings and facilities were erected on the site to support the lighthouse keepers and their families, and to provide infrastructural support to the operation of the lighthouse station. Most of these do not survive as intact structures, but all of them are represented on site by remnants in the ground, so that the layout and purposes of the lighthouse station are able to be interpreted to visitors. The Assistant Keeper's house does survive, and has been adapted for use as a Department of Conservation hut for overnight visitors. It is also the location of interpretative material used to describe the history of the lighthouse station and the life of its former residents. This interpretation happens both physically and virtually through a website.
These former buildings or their sites, which are included in the registration, include the sites of the houses of the Principal Keeper, the Assistant Keeper and the Second Assistant Keeper, the landing and gantry, crane, tramway, whim and engine shed, vegetable garden, schoolhouse, signal hut, power house, kerosene store, boat shed, stores shed, engine shed, water tank, workshop and forge, pump house, fowl houses and cow bails.
Lighthouse keepers and their families represent a distinct community within New Zealand society. Keepers moved from one location to another, but also developed quite intense and not always easy relationships with other personnel at the lighthouse where they were based. From the many primary resources, both official and private, it has been possible to develop a detailed picture of the way of life of the keepers at Cape Brett and their families, and this material is used by the Department of Conservation to interpret the history of the site to visitors, both physically and virtually through a website. Because so much physical evidence of the lighthouse settlement remains, it is possible for visitors to gain a good appreciation of what life was like, so that the buildings and other physical remains can be brought to life though the stories of the people who once lived and worked there.
Marine Department determines to construct a lighthouse at Cape Brett
Construction of Cape Brett Lighthouse commences
First keepers and their families arrive. February 21 Cape Brett Lighthouse first illuminated
Lighthouse converted to electricity provided by diesel generator.
Lighthouse connected to National Electricity Grid
Lighthouse keepers and families withdrawn as fully automated beacon installed.
5 October Light in Cape Brett Lighthouse tower used for the last time.
6 October Electronic beacon illuminated for first time.
Assistant Keeper's former house opened as Department of Conservation hut
Maritime Safety Authority (now Maritime NZ) advises NZHPT of its intention to demolish Cape Brett Lighthouse
Department of Conservation paints the exterior of the by then very rusted tower.
Lighthouse - Iron tower, glass and brass lantern and optics, copper dome. Other lighthouse station buildings were predominantly timber, with the surviving elements being mostly concrete footings and foundations.
Public NZAA Number
24th April 2009
Report Written By
Stuart Park, Christen McAlpine
Bella Bathurst, 'The Lighthouse Stevensons: the extraordinary story of the building of the Scottish lighthouses by the ancestors of Robert Louis Stevenson,' London, 1999
H Beaglehole, Lighting the Coast: a history of New Zealand's coastal lighthouse system, Canterbury UP, 2006
G. Churchman, New Zealand Lighthouses, Wellington, 1989
Cyclopedia of New Zealand, 1902
Cyclopedia Company, Industrial, descriptive, historical, biographical facts, figures, illustrations, Wellington, N.Z, 1897-1908, Vol.2, Christchurch, 1902
Department of Conservation
Department of Conservation
New Zealand Lighthouses: a national heritage identification study 2003
John Ross, Lighthouses of New Zealand, Palmerston North: Dunmore Press, 1975
Helen Beaglehole, Always the Sound of the Sea: New Zealand Lighthouse Keepers' Lives Craig Potton 2009
Chance Bros, 1910
Chance Bros, A Few Notes on Modern Lighthouse Practice Birmingham 1910
C W N Ingram, New Zealand Shipwrecks 1795 - 1970 Reed 1972
Merata Kawharu, Tahuhu Kōrero: the sayings of Taitokerau Auckland 2008
Christen McAlpine, Beacon of the Bay: the Cape Brett Lighthouse Settlement and its Families Department of Conservation, Kerikeri. 2008
A fully referenced Registration report is available from the NZHPT Northland Area Office.
Please note that entry on the New Zealand Heritage List/Rarangi Korero identifies only the heritage values of the property concerned, and should not be construed as advice on the state of the property, or as a comment of its soundness or safety, including in regard to earthquake risk, safety in the event of fire, or insanitary conditions.