1980 Wild Heerbrugg TC1 total station

The Wild Heerbrugg Sercel TC1 total station.
Figure 1: The Wild Heerbrugg Sercel TC1 total station.
I was given this total station in 2009. According to the last owner and based on the manual the instrument was made around 1980 by the Swiss company Wild Heerbrugg.

Development
The Wild TC1 was developed in 1978 and was the first total station that measured distances coaxial (so through or rather around the telescope as the telescope consists of two concentric lenses, the outer one of which was used to measure distances, see figure 8). Before the TC1 total stations measured the distance using separate optics above the telescope, causing distance errors when observing at steep vertical angles. Using a coaxial EDM meant the same point that was used to observe the vertical angle at was used to measure the slope distance to.

As can be told by the logo on the side of the instrument (see figure 4) the TC1 was a combined development of Wild Heerbrugg and Sercel, a well known manufacturer of various types of positioning systems as Syledis and high-end GPS receivers. Sercel has been responsible for various EDMs that were produced by Wild including the one on the TC1.1 Their cooperation was however not solely confined to EDMs, but also in other fields as aerial photogrammetry.2

The TC1 was capable of measuring horizontal and vertical angles and slope distances, which could be stored using an accessory cassette tape recorder that was mounted on top of the instrument (see figure 3). For comparison: the period Kern E1 in the collection was an electronic theodolite with a detachable distance meter and external storage. The Wild TC1 had all parts fully integrated in one instrument (although it has to be said that the recorder was detachable).

The Wild Heerbrugg Sercel TC1 from the other side.
Figure 2: The Wild Heerbrugg Sercel TC1 from the other side.
Provenance
In 1980 the instrument was - together with several others - purchased by DOSbouw (the joint venture that built the Dutch Delta Works in the southern province of Zeeland).

They were used for standard land surveying but also served as a back-up for the AGA/Minilir system (see figure 18 and figure 19) to position the vessels Ostrea, Macoma and Cardium. In order to do the latter the cassette recorder units were modified, replacing the recorder by telemetry (see figure 14), which allowed the measured data to be received on board of them. The TC1 was also used for an independent position check for the Ostrea. For this dedicated software was written on a HP85 computer that allowed to monitor the vessel in 3D. According the evaluation report the instruments gave little trouble and were popular among the operators due their ease of use.3

After the Delta Works the instruments were passed on to the Survey Department (Meetkundige Dienst) of the Dutch government. This is when they received their inventory numbers and by sheer coincidence the one showed here receved the first of them labelled "TC 1/1" (see figure 6).

Some of the six TC1s went to the field organizations, while three of them ended up at the Mariene Geodesie department (GAM) where I and the previous owner of the instrument used to work.4 Here the TC1 was used for vessel offset measurements and the submersion of tunnel elements of the Zeeburgertunnel (1987-1989, see figure 16) and Willemspoortunnel (1990-1991, single "s" is the official spelling, for picture see figure 17).

The TC1 with the cassette tape recorder mounted.
Figure 3: The TC1 with the cassette tape recorder mounted.
In August 1998 the previous owner was given the instrument when he left the Dutch Survey Department. In his spare time he used it several times to help the rowing club where his son was an active member, setting out the finish line and renovating the shore protection. Last year (2008) the instrument stopped functioning after which he decided to donate it to my collection.

Accuracy
Being an electronic total station the TC1 can be used in sexagesimal degrees (360 divisions in a full circle) and gon/grad mode (400 divisions in a full circle) by flipping a switch (see figure 7). The instrument has a compensator for the vertical circle and has an angular resolution of 3.24" (0.0011 gon) while the standard deviation of an observation in two faces is about 2" (0.0006 gon) horizontally and 3" (0.0010 gon) vertically.

According to the specifications the distance measurements have an accuracy of 0.005m (up to 1400 metres with three prisms and 8 seconds measuring time) or 0.005 - 0.015mm (up to 2000 metres with three prisms and 15 seconds measuring time). Horizontal and vertical distances can automatically be calculated and are corrected for refraction (k=0.13) and ppm which can be set with a switch on the side of the instrument.

At the time it first saw the market the Wild TC1 would have cost roughly fl.50,000,-.

The instrument
The instrument came complete with its modified cassette tape recorder, power supply, transportation boxes, and various small accessories like the reticle illumination (see figure 9 and figure 15). A period Wild Heerbrugg tripod was already in the collection to make the set complete. Sadly enough the TC1 stopped functioning properly in 2008 (see figure 11), so I could not put it to the test. Even an attempt by one of the Leica certified service stations here in the Netherlands did not get it back into working order.

On the scales it reaches a whopping 10 kilograms (14.5 kilograms with the box). The cassette recorder comes in a separate box and adds another few kilograms to it. Compared to this my Leica TCRA1101 total station I use for my work is a lightweight at only 6 kilograms (10kg with the box).

Notes

[1]: See the Distance meters page at The Virtual Archive of Wild-Heerbrugg
[2]: R. Brossier, C. Million, A. Reynes, "Photogrammetric Applications of Sercel GPS TRSS-B Receiver at Institut Geographique National - France", (St. Mande, 1988).
[3]: DOSbouw/RWS, Evaluatie MACOSDOS survey, v 2.1, February 1984, p.55.
[4]: The previous owner started working at the Survey Department straight after the Delta Works were finished, while I entered in 1996 and left in 2000.

Figure reference
figure 16 - figure 19: collection A.P.M. Pieters.

If you have any questions and/or remarks please let me know.

The Wild Heerbrugg Sercel logo of the TC1.
Figure 4: The Wild Heerbrugg Sercel logo of the TC1.
 
Officially the instrument was a "Wild Tachymat TC1".
Figure 5: Officially the instrument was a "Wild Tachymat TC1".

The Rijkswaterstaat inventory number "TC 1/1".
Figure 6: The Rijkswaterstaat inventory number "TC 1/1".
 
Adjustment of the units, ppm and prism constant is done using these switches.
Figure 7: Adjustment of the units, ppm and prism constant is done using these switches.

A circular filter dims the signal when measuring short distances.
Figure 8: A circular filter dims the signal when measuring short distances.
 
The filter and reticle illumination attachment mounted on the objective.
Figure 9: The filter and reticle illumination attachment mounted on the objective.

The keyboard has transparent rubber keys.
Figure 10: The keyboard has transparent rubber keys.
 
The display showing erroneous data.
Figure 11: The display showing erroneous data.

A view at the built in coincidence vial directly under the ocular.
Figure 12: A view at the built in coincidence vial directly under the ocular.
 
The image is erect and there is a central cross, but no stadia hairs.
Figure 13: The image is erect and there is a central cross, but no stadia hairs.

The cassette recorder has been removed from the top unit and was replaced by telemetry.
Figure 14: The cassette recorder has been removed from the top unit and was replaced by telemetry.
 
The instrument (left) and telemetry box in their cases.
Figure 15: The instrument (left) and telemetry box in their cases.

A.P.M. Pieters and B. Valstar tracking a tunnel element of the Zeeburgertunnel.
Figure 16: A.P.M. Pieters and B. Valstar tracking a tunnel element of the Zeeburgertunnel.
 
Ad Pieters at work with TC1s at the Willemspoor Tunnel Submersion Works.
Figure 17: Ad Pieters at work with TC1s at the Willemspoor Tunnel Submersion Works.

One of the Dutch TC1s next to a Koni 007 level and the AGA/Minilir autotracking total station.
Figure 18: One of the Dutch TC1s next to a Koni 007 level and the AGA/Minilir autotracking total station.
 
Lou de Jonge with Wild TC1 (right) and AGA/Minilir
Figure 19: Lou de Jonge with Wild TC1 (right) and AGA/Minilir

Surveyor's crosses Geodetic Sextants Theodolites Total Stations Levels Standards Tools Firms
1980 SAT AGA-Minilir 1980 Wild TC1 1984 Kern E1 1986 Geodimeter System 400 1992 Krupp Atlas PolarTrack 1999 Leica TCRA 1101