Rolling Ball Clock

Picture showing people in front of the Rolling Ball Clock.

The Rolling Ball Clock is a unique oversize timepiece located next to Claphams National Clock Museum at Whangārei's Town Basin marina.

This free attraction tells the time using 35 balls, which display the time on a series of timing racks showing hours, minutes and seconds. 

The balls move on stainless steel tracks performing loop the loop and even riding in elevators to create a memorable experience for visitors of all ages.

The clock runs for 12 hours a day, between the hours of 8:00am and 8:00pm.

A kinetic sculpture, as well as a clock, it uses the scientific principles of balance, equilibrium, and movement, and is constructed of many connected moving parts including gears, wheels and chains.

The Rolling Ball Clock was created through years of research and development by a talented group of local community members with engineering backgrounds. The clock opened for the public on 7 April 2022.

How it works

The clock sculpture tells the time using four connected systems

  • lifting mechanism
  • time indication racks
  • track elements
  • control system

The balls are transported on a lifting mechanism of three large gear wheels

Three large gear wheels transport the balls from the lowest level to the highest level of the sculpture.

Lifting gear mechanism at the Rolling Ball Clock.

The lowest and largest gear has attachments for four balls, the middle gear has attachments for three balls and the upper and the smallest gear has attachments for two balls. Balls are raised at a constant rate of four per minute. 

The balls are released from the top of the lift and roll to the uppermost time indication rack.

Timing indication racks (T1, T2, T3, T4) show the time of day by the number of balls resting on them

Next to the position of each ball in the timing racks is a number showing the seconds, minutes and hours of time the clock is indicating.

Time arm containing the balls in the Rolling Ball Clock.

Timing indicator rack one (T1) - the uppermost rack is the one minute display, with 15,30 and 45 second intervals marked. The addition of the 60 second ball causes the rack to over balance and discharge all of the balls. One ball goes to T2 with the remaining balls going to the holding tracks.

Timing indicator rack two (T2) - the next track down is the ten minute display, with one through to nine, minute intervals marked. The addition of the tenth minute ball from T1 causes the rack to over balance and discharge all of the balls. One ball goes to T3 with the remaining nine balls going to the holding tracks.

Timing indicator rack 3 (T3) - the next lower rack is the one hour display, with 10, 20, 30, 40, and 50 minute intervals marked. The addition of the 60 minute ball from T2 causes the rack to over balance and discharge all of the balls. One ball goes to T4 with the remaining five balls going to the holding tracks.

Timing Indicator Rack 4 (T4) - the lowest rack is the 12 hour display, with 1 hour through to 12 hour intervals marked. The addition of the 13th hour ball from T3 causes the rack to over balance and discharge 12 balls to the holding tracks. One ball is permanently fixed at the one hour position to how if the time is am or pm.

Track elements

The sculpture features spirals, a Newton’s cradle, racing balls, an undulating track, a loop-the-loop, banked corners, a sawtooth track, and switches.

The spiral loop of the Rolling Ball Clock.

A clever control system ensures the clock keeps accurate time

The clock is designed to only require maintenance every six months (when a daylight savings time adjustment is made). In that six months the clock will have lifted and run over one million balls through the clock.

Control System machine of the Rolling Ball Clock.

The control system is made of three main components.

The brain

The brain of the sculpture is a computer called a programmable logic controller, or PLC. This has an accurate, digital time-of-day clock, that it uses to control when the balls are released so that the correct time shows on the front of the clock.

The Cog Drive (servomotor)

The programmable logic controller controls the speed of the servomotor that rotates the clock’s main cog.

Keeping the clock accurate 

There are two fine-tuning sensors keeping the clock's time accurate. The first ensures one revolution per second of the mechanism that pulls the arm causing the ticking motion of the clock's main cog.

The second detects if a ball is released every 15 seconds. If a ball arrives slightly early or late, the target speed of the servomotor's control loop will be adjusted so that the next ball is closer to the 15 second timing mark.

Design considerations

When designing the clock, minimising the wear on the balls was an important consideration. This is achieved by controlling the ball speeds by varying the track width and slope.

Close up of ball in Rolling Ball Clock.

Slight changes to the track width allow acceleration of individual balls and keep the balls separated. Ball to ball contact would dramatically increase the wear and scuffs on the surface of the balls. 

The balls have both kinetic and rotational energy. Reducing the track angles allows for slower balls speeds and minimises the impact when the balls are stopped. 

Māori cultural features

Various design elements, concepts and meanings from Māori culture are strongly integrated into the clock and its operations.

The mechanical operations are seen as a miniature version of the universe. The movement of spheres in the structure is compared to the movement of planets in the universe.

The central pou shows the story of how Maui slowed down the sun and symbolizes the invisible energy that kept Rangi ( Sky Father) separated from Papatuanuku ( Mother Earth).

The striking wave form of the roof incorporates symbols representing our people (Tangata), the waters (Tangaroa, waitī and waitā), the moon (Marama) and Rona, the controller of the tides.

The door represents our universe and the Milky Way (Mangoroa or Te Ikaroa).

Other features include using the Maramataka in central pou to measure time and seasons using phases of the moon.

The history of rolling ball clocks

Sir William Congreve is credited with inventing the first ever rolling ball clock which he patented in 1808. 

It told time in a new way, using a ball rolling on a zig-zagging track which pivoted and tipped instead of using a conventional pendulum to provide the timekeeping. 

Unfortunately, it proved unreliable, with the ball speed varying depending on things like the cleanliness of the track and the ball. 

In the 1970s, Harley Mayenschein invented and patented a rolling ball clock made from wood and steel balls. A plastic model of this clock is in the Claphams Clock National Museum. It uses small stainless ball bearings and was the inspiration for the large scale Whangārei creation.


Educational resources

Laws of physics and precise calculations are involved in the operation of the clock.

The education opportunities for primary school students is to understand the units of time, and secondary school students can learn calculations of balls going around loops and banking without falling off.

The below questionnaires can be used to develop an understanding for the students and test their observation and understanding.

Questionnaires for school students(PDF, 296KB)

Questionnaire answers(PDF, 14MB)

The About Time project

The Rolling Ball Clock was designed and built by a local group under the project name About Time.

The small team started working on the project in 2008 and spent 14 years making the clock a reality.

Group photo of members of the About Time team.

The team (pictured from the left):

 Henk Oosterbroek - Boat builder/designer, Phil Collins - Design engineer, Te Warihi and Philip Hetaraka - Cultural Advisors, Graham Brice - patron, Reg Shaw - Rolls Royce draughtsman, Roger Reynolds - Electrical engineer, Vic Pitman (kneeling) - Chairman, Warren Thomas - Beca Project Manager, and Pete Romer - Graphic designer. Insert left: Sandra McKersey and Jan Ahlers - Fundraising. Not shown, Brian Adcock and Malcolm Hawthorne who are sadly no longer with us.

The project received funding from Government's Provincial Growth Fund, Council and many other local sponsors.

Financial support

Operating costs

There are ongoing cost associated with running the clock 12 hours each day. This includes the temperature controlled enclosure (heat pump), lighting, security cameras and the maintenance of the clock.

There is a monthly routine check to clean and polish the balls and maintain the tracks.

Next to the clock, there is an EFTPOS terminal for donations to be made towards these ongoing operational costs.

Building costs

The cost of over one million dollars was contributed by the following supporters:

Principal funders:

  • Whangarei District Council
  • Provincial Growth Fund
  • Northland Community Foundation

Consultants / designers:

  • Cook Costello
  • Axia
  • Tui Technology
  • Beca

Contractors / suppliers:

  • Absolute Stainless
  • GHK Piling
  • GFM Branding Solutions
  • Culham Engineering
  • Golden Bay Cement
  • Virgin Concrete
  • McKay
  • Metro Performance Glass
  • Phoenix Metalman Recyclers
  • Art in Stone
  • Calitec
  • Fully Glazed
  • Stone Mats
  • Ross Bourke

Golden funders:

  • Hansen
  • People Potential
  • Colin Edwards
  • Hanley Hutchinson
  • Murray Holdaway and family
  • Sandra McKersey

Silver funders:

  • Graham Brice
  • Henk Oosterbroek

Bronze funders:

  • Graeme Johnson Jewels and Time
  • Rotary Whangarei South
  • SKF
  • Whangārei ITM
  • Reyburn & Bryant


Town Basin, Whangārei 0110  View Map

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