Refurbishment 2018

• Status: Completed
• 1st of 3 construction phases
• New stainless steel basins
• Renovation of swimming pool technology
• Water level increase
• 2014 to 2018

Design:

• Stainless steel pool cladding
• Raising the water level to ground level
• Absorption of splash water through circumferential channel at ground level
• Stainless steel slide and play stream

Key data:

• Implementation of technical renovation: 2014 - 2015
• Planning building construction: Glashaus Architekten PSG, Aachen
• Technical planning: INCO, Ingenieurbüro GmbH, Aachen
• Implementation of structural renovation of the pool: 2017 - 2018

The flow rate was tested with the aid of a dyeing test.

Current status:
- Longitudinal flow in both pools
- Water discharge 100% via the front sides
- No surge tank - State of the art 1961: The displacement water (i.e. the water that "swells" over the edge when the pool is used) is discharged directly into the sewer and not collected.

Water treatment / filtration:
There are three filters dating from 1961. Some of the internal coatings have flaked off due to age, the filter containers are deformed and the filter system's stability was predicted to be a maximum of three years.

Piping:
The piping system is worn out after 44 years. The pipe sections are encased in concrete, making repair impossible. In addition, the cement linings have flaked off due to age, so there is no longer any corrosion protection. The consequences were already evident in pipe bursts in 2012 and 2014.

Refurbishment of the pools:

• Use of stainless steel basins
• Change to a vertical flow
• A new swimming pool cover prevents the pool from cooling down at night
• 100 % water drainage via channel: raise water level, large circumferential channel, level with pool surround

Refurbishment of the technology
Two new surge tanks are being built. The water that "swells over the edge", the so-called displacement water, is collected here, filtered and fed back into the cycle. A new sludge water tank is used to collect the backwash water after cleaning the filters. The sediment settles in this tank and the residual water can be fed into the sewer system.

Underground structure for the technology:
The above-mentioned tanks and the pump chamber are housed in a newly constructed underground structure.

Filter house
The filter house is renovated and the filter technology is completely renewed.

In 2014, the technology is 44 years old.

The large pool was divided into two separate pools during the renovation in 1970: A 50x21 meter swimmer's pool and a 25x32 meter non-swimmer's pool were created.

A large 100-meter pool was built in 1920.

The picture shows the inspection accesses for the underground tanks
(surge water, sludge water, pump chamber). This is where the landing platforms were later installed.

The circulation pumps of the NSB (non-swimmer pool) in the pump chamber, directly in front of the splash water tank.

The viewing hatch with a view into the surge tank. The fiber catcher in front of the pump holds back coarse impurities such as leaves or grass. This is cleaned manually every day.

Three-dimensional implementation planning of the installation system.

The outdated filter technology was removed from the filter house. The concrete walls were cleaned with a high-pressure cleaner at 3000 bar. This also removed spalling from the old concrete covering and corrosion on the reinforcement bars. A new covering of 3 cm was applied using shotcrete to protect the reinforcement from chlorine in particular.
A floor slab was installed and new channels were created for the waste water. The windows were also replaced.

The pump chamber is installed underground. The surge tanks and sludge water tanks are housed here. There is pressing groundwater in the area of the shaft. Therefore, sheet pile walls must first be installed and the groundwater lowered. A load-bearing base, a so-called excavator mattress consisting of wooden beams, must first be constructed for the excavator used to drive the sheet piles into the ground. The pile-driving excavator only works at 24 hertz in order to generate as little vibration as possible in the existing buildings and in the basins.