Mathias Schlösser - HafenCity University Hamburg

Enterpa Engenharia Ltda. São PauloIn October 2007 the first ever international exchange took place between students of the HafenCity University in Hamburg, Germany and Enterpa Engenharia Ltda. of São Paulo in Brazil. During the Geomatics diploma course it is obligatory to attend a practical trainee program, the aim being for the exchange to improve practical knowledge and give an opportunity to apply theory of study. Both combined skills will prepare the students for the real workplace after their studies.

After my apprenticeship as a draughtsman I decided to study geomatics, attracted by the wide variety of working areas. I specialised in hydrography because it is one of the most interesting working areas. Students can work in dredging, maritime construction, pipeline, creation of nautical charts and many others.

The HafenCity University Hamburg (HCU Hamburg) is a university for geomatics (surveying + hydrography), architecture, civil engineering and city planning. The department of geomatics includes hydrography, geodesy, engineering, geodesy, photogrammetry, remote sensing, GIS and urban management.

The headquarters of Enterpa Engenharia Ltda. (Enterpa) is in São Paulo. Established in 1957, it has grown to be a big player in the Brazilian market for engineering and construction works and environmental management. The main activities of Enterpa Dredging are services for maritime, river and lake dredging, works in hydraulic landfills, underwater rock removal, and port and canal dredging and cleaning.

Work at Enterpa
One basic activity of dredging is to ensure safe and improved navigation in channels and harbours. Also it is necessary to expand waterways for upcoming economical activity.
The focus of the working project during the practical traineeship was the deepening of the channel to the COSIPA (Companhia Siderúrgica Paulista) terminal at Cubatao - Port of Santos. The Port of Santos is the largest and most important port in Brazil. Almost all container lines in South America use the profitable location for access to the business metropolis of São Paulo and the county of Minas Gerais, demanding an expansion of its infrastructure. A growing economy, especially an emerging country like Brazil with rising export of agrarian, ore and dry bulk goods, needs extended infrastructure. Transport on waterways compared to railways and roads has big advantages in terms of capacity and energy consumption.

The COSIPA terminal in the commune Cubatao is 15 kilometres upstream from the main port of Santos. To improve the current situation, the COSIPA company wants to deepen the waterway to least 12 metres. Although the channel of the Port of Santos is already at a depth of 12 metres it will be dredged up to a depth of 14 metres.

Enterpa’s task was to dredge the channel to the required depth. The mission of the department of bathymetry was to analyse the recent situation with the waterway and to monitor the dredging process.

Before dredging it is necessary to carry out an initial survey to register the current depth and state of the channel bed. This survey gives an overview about volumes and the locations for dredging. Also it is the reference point for final checking of the completed work.

The use of dual frequency single-beam echo sounder - 24/200 kHz - has the advantage of recognising solid and muddy bottoms at same time. Knowledge about the condition of the channel lets you choose your dredging hardware to maximise performance. The wrong equipment can damage your hardware and result in extra costs due to inefficiencies, as well as uncalibrated equipment. For this reason both hardware and software were calibrated and configured exactly before carrying out the survey.

The single-beam echo sounder was calibrated by bar check method, and GPS was checked for latency. The data acquisition was carried out using both software and paper registration. During the collection, all data were checked for validation. If there was transmission loss recognised, the complete profile line was re-done. All recorded data were backed up twice to ensure the correct quality standard for Enterpa.

Post-processing with data validation, cleaning, editing, volume calculation and chart plotting was done at Enterpa’s offices in São Paulo.

The calculation of volume needs a recent survey and an older survey, with the same frequency of single-beam echo sounder, for comparison of the dredged volume. There are various methods of calculation at post-processing software, depending on the client and the composition of the location of the dredge. With a chart print it is possible to see the recent status of the dredging process. After every volume calculation the dredge crew get a new XYZ-file with new instructions of a location to dredge until final depth.

One main problem during surveys and post-processing is the influence of fluid mud. Caused by dredging and the resultant turbulence in the water column, mud particles scatter the acoustic signal and falsify correct depth. Fluid mud is still one of the biggest problems of ordinary single-beam echo sounding. To get the best results, it is necessary to make a compromise on survey channels and on dredge channels. Both at the same time is hardly possible because of the turbulence in the water column. To stop dredging means to lose money. But badly surveyed depths - caused by fluid mud - means losing money too. Inaccurate depths can cause areas to not be sufficiently dredged or to be over-dredged. Re-dredging again means additional costs for fuel and crew. Dredging above tolerance limits also results in penalty payments to the client.

 In the case of this project, the bathymetry team surveyed the project area weekly and monitored the status of the dredging process, made post-processing, volume calculations and updated dredge specifications. Alongside the dredging job, I was also involved in business administration. My task was to look for, compare and negotiate with international hardware manufacturers, because Enterpa Engenharia Ltda. wanted to buy new equipment to improve the quality of work flow and to expand its field of work.

To guarantee the quality of bathymetry surveys I created a quality management handbook to prevent human errors.

During the practical trainee period the 1st annual WEDA – Brazil Chapter Conference in Rio de Janeiro took place. During the conference, many professionals presented interesting topics about the dredging business and law, dredging works and equipment. It was a pleasure to meet like-minded people and have conversations about the dredging business. Also I had the opportunity to talk with sales managers and manufacturers about negotiations and business, which before I had only done by mail.

It was impressive to find out that the world’s most famous beaches of Ipanema and Copacabana were designed by dredging at the beginning of the second half of the last century!

Conclusion
Hydrography and dredging in particular is one of the most interesting jobs one can do. To make something visible, to visualise something where nobody has walked or seen before is incredible. The business of hydrography is growing and promises many varied projects, in the fields of dredging, oil and gas, pipelines, maritime construction, border land and the creation of nautical charts.

To work in and experience a foreign country, with a foreign language is an unforgettable moment and character-forming. During the trainee period I could apply and expand my study knowledge about nautical surveying and business administration. I can absolutely recommend anyone to go to foreign countries and work there.

Enterpa Engenharia Ltda. is a serious and responsible company in business and social engagement. After my graduation I hope to get an opportunity to work in the dredging business, maybe at Enterpa Engenharia.

Many thanks to the team of Enterpa Engenharia Ltda.; especially to the supervisor of bathymetry, J. Bartolomeu F. Fontes.

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