The Gisborne Earthquake of 1966. Part 3: The Aftermath

The scientific and engineering collaboration which resulted in a joint publication about the Gisborne earthquake of the 5th of March 1966 provides a valuable insight into the causes of, effects of, and restorative work required as a result of a large earthquake. Unlike a modern day report which would probably be toned down so as not to offend anyone, the conclusions and recommendations were clear and to the point.

The publication, called Gisborne Earthquake New Zealand March 1966 was issued as Bulletin 194 by the Department of Scientific and Industrial Research in 1969. It contains numerous diagrams, photographs and plans to illustrate its findings.

As a result of the earthquake, the report noted that surveyors from the Lands & Survey Department found “that the location of [survey] marks was unaltered, but that there had been some variation in levels since the previous check was made in 1924. The levels suggest that Whataupoko has settled and Kaiti has risen with respect to the central city area. The maximum variation consisted of a lowering of 1½ in. [38 mm] in Whataupoko and a rise of 1 in. [25 mm] in Kaiti. The maximum variation in the central city area was ½ in [13 mm]. It should be borne in mind, however, that there have been at least four earthquakes of this intensity since the previous check of levels.”

Whilst Gisborne had been given a “tidy-up” after the damaging earthquakes of 1931 and 1932, the report noted that many of the actual repairs had been cosmetic. This allowed the 1966 event to easily display past damage and add to it.

My experience is that the town actually paid attention after this, and this resulted in major improvements to premises in the city area. Some of the old landmark buildings had to go, while others were strengthened and had dangerous parapets removed. During the next few years some cherished venues such as The Gisborne Hotel and the opera house fell to the wrecker’s ball, as did the Gisborne Police Station (formerly the Maori Land Court) and many old brick structures whose function had changed over the years.

The most seriously damaged building, the Chief Post Office remained standing but barricaded for some time after the earthquake. I can remember walking through its capacious entrance on the corner of Gladstone Road and Customhouse Street to buy stamps before the quake. It seemed sad to see the entrance barred by timbers and the footpath roped off afterward. The building had a garishness that somehow was attractive, but demolition to give us Endeavour Park was the right decision.

The loss of its local headquarters resulted in various functions of the Post Office being farmed out to different buildings in the city. The entrance to the old telephone exchange on the corner of Customhouse Street and Childers Road once again became a public entrance when the telegraph office opened a public counter there post-quake. I use the term “counter” advisedly, as it was a mere hatch in a door with a tiny rest where telegrams could be lodged and collected. The savings bank moved into rather spacious accommodation on the corner of Gladstone Road and Lowe Street while the mailroom crossed the Taruheru to the Army Hall in Fitzherbert Street.

The various locations were within easy walking distance, and the public seemed to accept the minor inconvenience. The Army Hall’s parade ground provided ample parking for bulk mail users and Post Office boxholders, but the contraction of their accommodation must’ve irked the army recruiters. The building’s use for mail services became so entrenched in my mind that the occasional reclamation of the ground for army parade and drill seemed incongruous.

It would not be until the mid-1970s that the Post Office divisions would all be housed together again in their new purpose-built CPO building in Grey Street.

One of the wisest post-earthquake decisions was made by the Hawke’s Bay Education Board with regard to the damaged infant block at Mangapapa School. Instead of trying to patch up the old structure, the board acted with alacrity by demolishing the building and putting up a new wooden building within 2 months of the earthquake.

C. M. Strachan of the Ministry of Works monitored the demolition work and noted that, when the roof framing was stripped and the tie rods loosened, the building spread by 2 inches [51 mm]. He further noted that “The 12 in. x 12 in. [300 mm x 300 mm] concrete band at roof level … contained only one 3/4 in. [19 mm] diameter steel rod placed in the middle of the beam and about 1 in. [25 mm] up from the bottom. There were no laps in the reinforcement, which was joined only by interlocking hooks. This method of jointing was also used at the corners and therefore created a hinge at each joint. When the pillars between the steel window frames were removed, the concrete band dropped, as it could not span the 8 and 10 ft [2.4 m to 3 m] gaps between the brick mullions. The concrete band had only been resting on the brickwork, without any connection to it.”

Strachan also found that a number of large stones had been used as “plums” to save on concrete in the foundations. In addition, one chimney had moved more than 3 in. [76 mm] between the ceiling and the roof. The future pupils at the school had been fortunate that their board had decided to act decisively in demolishing the structure instead of patching it up according to five recommendations which included this doozy: “The classrooms be used for older children so that evacuation could be quicker…”

Presumably Strachan’s detailed observations led to the early demolition of the damaged northern single-storey wing at Gisborne Boys’ High School which had gone by the time I studied there in the early 1970s. The post-quake inspection there had discovered similar damaged concrete bands constructed of poor-quality, porous Kaiti shingle in which the moisture penetration had rusted the reinforcement to the point at which spalling had commenced.

A look through historical records for Gisborne shows that the lack of suitable rock and shingle locally has continuously impacted the construction of roads and buildings. Time after time, the town’s pioneers surfaced roads with material from Kaiti, Waihirere and further afield from Patutahi only to find it breaking down under the onslaught of moisture. In his book Historic Poverty Bay and the East Coast N.I., N.Z., J.A. Mackay tells us that the roading problem wasn’t properly solved until the acquisition of a hot-mix plant in 1926. So it’s not surprising that inferior stone was to be found in buildings of the time.

Meanwhile, at home, life returned to normal after the earthquake. The chimney above the rumpus room was re-topped and the large fireplace was able to be used again. It was to be the focal point of many a dark night when we made “toastie pies” in a long-handled griddle during power cuts. The floor continued to have a slope on it and the wonderfully large expanse of space could no longer be used for playing marbles or bowls when it was wet outside.

The sitting room chimney was repaired too. The elegant tiled fireplace had an unusual steel shutter that allowed it to be closed down when the fire was not lit on a windy night – which was rare. This room was always snug on a winter’s night, and the fire was easily stirred up if we had to get up in the early morning hours to listen to a radio commentary during an All Black tour of South Africa.

The chimney and fireplace in the master bedroom were too badly damaged, and the chimney was capped shortly after the quake. Its apparent advance into the room was never corrected before we moved on to another house some years later.

And the window weights kept up their clanking. Every sizeable earthquake was always serenaded by a peal of window weights beating time on the inside of the walls. Their sound remains vivid in my memory.

Leave a Reply