In 1834, the lantern had 128 small panes of glass that had to be kept clean. A Commission appointed in that year reported that nothing could be done to improve the light until a new iron lantern was installed. This was not done until 1864. In that year a new iron lantern with plate glass windows and a light with reflectors was installed. Mariners complained that the top of the tower was often obscured by fog. Serious consideration was given to lowering the height of the tower.
|© Peter MacCulloch|
|Sambro Lighthouse c. 1995|
In 1906, an extra 22 feet was added to the height of the tower. At the same time a first order Fresnel dioptric lens manufactured in France was installed, marking the light as one of Canada's major coastal beacons. By this time, 39 years after Confederation, the light was being staffed by the Coast Guard of the Government of the Dominion of Canada.
In January of 1950, lightkeeper W. A. Smith noticed that the lighthouse was swaying! It was found to be leaning by 20 centimeters. In the spring, excavations at the base discovered that the mortar was cracked and some stones were loose. In the fall, grout was pressure-pumped in and a concrete collar about 90 cm. thick and 2 m. high was installed to reinforce the base.
In 1966 the classic iron lantern which crowned the tower was replaced with aluminium and a 36 inch airport beacon replaced the huge lens. This DCB36 (36 inch diameter) airport beacon has a range of 24 miles and flashes every 5 seconds. The lens now greets visitors to the Maritime Museum of the Atlantic in Halifax, where its complex optics can be closely examined and admired. The tower height became its current height: 25 metres (82 ft), base to top.
For many years Sambro was equipped with cannons to answer ship's signals in fog. Later, a steam fog horn was installed, then bomb rockets, after that acetylene guns, and finally, in 1963, a diaphone. In 2008 the diaphone was replaced by electonic horns.
In 1937 Sambro Lighthouse was designated a National Historic Site and a plaque placed in the village of Sambro.
In 1996 the lighthouse received Federal Heritage Review Board Classified status, the highest ranking status for Canadian Government Heritage Buildings. In part, the review stated: "The lighttower at Sambro Island was designated Classified for its historical associations, its environmental significance, and also for its architectural design. One of the most historically important lighthouses in Canada due to its age and its association with Halifax Harbour's marine traffic for over 235 years, this stone and concrete tower is considered the oldest operating lighthouse in North America. It has seen many developments in lighthouse design and apparatus technology, from its beginnings as a massive stone structure with a wood-framed sash-windowed lantern. The character of Sambro Island and its built heritage remains virtually unchanged. The lighthouse, by its very function and design, has been the dominant structure on the island since its completion ca.1760. The gas house and a number of small wooden structures, including a fog alarm building, are scattered across the rugged, exposed site and act as an appropriate foil to the lighthouse. The simple, utilitarian character of the site should be protected."
Careful research in 2004 has established that Sambro Lighthouse is the oldest standing and operating lighthouse in the Americas.