Australian Watch Club

Subscribe to Our Newsletter 

Grönefeld 1969 DeltaWorks

Bart and Tim Grönefeld, aka ‘The Horological Brothers’, are third generation

watchmakers. Like their forebears, they live and work in Oldenzaal in the

Netherlands. They are proud of their heritage as well as the nation they call


Inspired by the Dutch Delta Works, The Horological Brothers have conceived

their first sports utility watch, the aptly named 1969 DeltaWorks which also

references the year Bart was born. The model is designed to cope with the perils

of water ingress and shocks while still upholding the elevated standards of

horology and traditional craftsmanship that are synonymous with the Grönefeld


The dial of the 1969 DeltaWorks presents the essentials of time, namely, hours,

minutes and seconds. There is nothing superfluous. In fact, when designing the

watch, Bart and Tim were keen to ensure that the dial imparted information in a

clear, intelligible format. To deliver peerless legibility, day or night, the hands

and hour markers are treated with Super-LumiNova®, that produces a blue glow

in restricted light.

While the dial is highly practical it is still enriched with numerous details. For

example, the hour track sits on a higher plane than the central dial area and

small seconds display. The plump lancine-style hour and minute hands deliver

impressive readability even in the most challenging conditions. At the fulcrum of

the hands, the ‘centres’ are black polished to a gleaming conclusion.

The small seconds display features ‘60’, presented in an orange hue, a respectful

nod to the brothers’ homeland. Likewise, the country of origin is proudly

proclaimed at the base of the dial.

The 1969 DeltaWorks is presented in a 45mm stainless steel case, measuring

12.5mm in height. The case features an integrated strap that ergonomically

encircles the wrist, conferring a high degree of wearer comfort while appearing

smaller than its stated dimensions would suggest. The scale of the case endows

the watch with a generously proportioned dial area, augmenting legibility but

without appearing unduly large. Every aspect of the case has been carefully


Two inserts are integrated within each caseband, steadfastly secured to the main

body of the case. The inserts are offered in two formats: stainless steel,

matching the case material, or titanium shrouded in coloured FKM rubber,

designed to match the shade of the strap. A notable attribute of the latter option

is that there is less risk of the case band picking up annoying scratches.

Throughout the composition, the case juxtaposes brushed and highly polished

surfaces, contributing to the model’s notable allure.

A triple-seal, screw-down crown mitigates the risk of dust or water ingress. In

addition, the crown features an ingenious safeguarding system. When the

Grönefeld logo on the crown is perpendicular to the dial and pointing upwards,

the triple-seal, screw-down crown delivers maximum protection. The sapphire

crystals, to the front and rear, are thicker than normal and, by default, stronger.

As a result of the aforementioned details, the watch is water resistant to 100m,

making it suitable for an array of leisure pursuits, including swimming, sailing

and windsurfing.

When conceiving the 1969 DeltaWorks, Bart & Tim were keen to ensure the

watch was suitable for daily wear and compatible with an active lifestyle. With

this in mind, they decided it must feature a self-winding movement

encompassing the same exalted finishing as other Grönefeld timepieces.

Put simply, the brother’s wouldn’t countenance any compromises. As such, the

resultant movement, the calibre G-06, is worthy of the term ‘Haute Horlogerie’.

Brand devotees may recognise the calibre G-06, an automatic movement first

used within the company’s 1941 Principia Automatic. However, while many

elements have been carried over to the 1969 DeltaWorks, there are some

additional details which enhance robustness, imbuing this version with its own

distinctive character.

For instance, a notable feature specific to this model is the distinctive oscillating

weight. The openworked architecture features four stainless steel arms,

presented in a double-spoke design. These arms are connected to an 18K gold

mass adorned with a wave motif. Each of the four arms is positioned beneath

the gold mass and projects beyond, sitting above a circular ledge. Should the

watch be subject to a sudden shock, the elongated arms will prevent the

oscillating mass touching the inside of the sapphire crystal or striking the bridges


The movement is intended for the most discerning watch collectors. The rotor is

completely hand finished and turns on ceramic ball bearings, preventing wear

and eliminating the need for lubrication. Meanwhile, the stainless-steel bridges

replicate the façades of traditional Dutch houses, termed ‘bell gables’. Each

bridge features a micro-blasted central section, framed with a hand-bevelled

gleaming edge. Some of the bridges also feature relief engraving. Each

movement is fitted with a plate engraved with ‘ΔW’ (signifying DeltaWorks)

along with its unique movement number.

The Grönefeld 5-arm, double spoke gear train wheels exhibit a contemporary

character, but their circular grained surfaces pay due reverence to fine

watchmaking tradition. Their design, as well as the bevelled escape wheel teeth,

prevent the oil from dissipating, thereby mitigating wear. The free-sprung

balance mitigates positional influence and delivers superior rate stability. The

escapement is adjusted to heat-cold, isochronism and six positions.

Gold chatons stand testament to the no-compromise specification of this

movement. In addition, the mirror polished screws feature chamfered rims and

slots. Numerous surfaces gleam, courtesy of the mirror-polishing which has been

patiently executed by time-served hands. The inventory of different decorations

includes snailed, grained, spotted and frosted surfaces, indulging the desires of


Once again, there are no compromises. Everything is reassuringly Grönefeld.

Join Australian Watch Club for more insight to the watch world, and safeguard your timepiece investment with Australian Watch Insurance, Australia’s only tailored insurance solution for your watches.

Read More

 BAUSELE Liqui Moly Bathurst 12 Hours race.
Roger Dubuis & Gianfranco Ritschel
Fears Watch Event
Grönefeld 1969 DeltaWorks

Subscribe to our newsletter