Tendering and construction

Tendering process

When the decision, planning and financing of a new snow production system is in place, the actual tendering and construction process starts. The first task is to obtain offers from suppliers of the snowmaking system components as well as from construction companies that can do the required earth work and assembly. To do this properly requires tendering documents that clearly describe the venue, specify the requirements and describe all components of the system.

For larger systems it is challenging for a venue owner (or the party initiating the process) to know all the details required for a good and fair tendering process, It is therfore quite common to organize a dialogue conference and one-to-one meetings with the interested snowmaking system suppliers. In this way the suppliers can be part of designing a good system, and help identify important elements for the tendering documents. It is important to take good notes and protocols from the dialogue conference, and make sure all interested suppliers and parties receive the same information.  

The tendering documents should describe the system requirements, and in a clear way what the potential providers are expected to deliver in their bid. Clarity is important such that the different bids and offers can be easily compared.

  • An example of a system requirement can be (for an alpine venue):
    • A topographical map showing the planned layout
    • A general description of the area:
      • Total slope/courses: 1000 m long, 30 m wide
      • Snow: 40 cm depth, density 400 kg/m3
      • Estimated temperature at startup: Wet-bulb from -8 to -4 °C
      • Production time: 150 hours
  • This will then enable the supplier to suggest a masterplan and give a price for the components

A snow production system consists of several parts and components, and the tender can therefore be divided into several parts that the bidders answer and provide a price for. Since most suppliers of snowmaking system components prefer to work with a separate construction company (who performs the required ground work), two tenders may be required.

  • Provide a masterplan that includes description and details for water intake, pumphouse and pumps, types and sizes of pipe, number of hydrants, number and types of suggested production units etc.
  • Cost for all parts shown in the masterplan, as well as automation software, education of staff, commissioning, service osv. 
  • Cost of providing and installing pumps
  • Cost of providing and installing air compressors 
  • Cost of delivering pipes and installing/connecting them 
  • Cost of delivering pits, valves and hydrants and installing them
  • Cost of the production units (fan guns or snow lances)
  • Cost of building the pump house*
  • Cost of installing power and data cables, and affiliated distribution boxes etc. *
  • Cost of digging ditches, eventual blasting, filling and compacting ditches after pipes, pits and cables are installed*

    * the marked lines are often a separate “construction tender”

It is also important to decide how to coordinate the construction work; will the ski club or venue owner be responsible for this, or will the project coordination be done by a general contractor that coordinates the work done by sub-contractors? This must the clarified in the tender documents and also be included in the cost sheet that the bidders provide (if they are expected to coordinate the project).  

The tender document could include the following sections:

  • Area layout, system requirements and functional description  
  • Criteria for comparing the bids
  • Criteria for awarding the winning bid 
  • Cost sheet with all components listed

It is also important that the criteria used for the internal evaluation are discussed and written down before the bids are received and evaluated.   Awarding the winning bid must take place according to those pre-determined criteria, and be well documented in case any of the bidders decide to submit a complaint. The evaluation criteria may consist of:

  • Cost 
  • The provider’s functional, technical and environmental qualities
    • Quality of the master plan 
    • Quality of the production units, its production capacity in different temperatures, energy usage, throwing capacity, noise, weight, etc  
    • Environmental certificats, etc. 
  • The system’s operational qualities
    • Ease of operation and control systems
    • Automation
    • Education, service plans included etc.

At many venues the snow production needs to take place in marginal weather conditions, especially at startup times with mild and changing temperatures. These conditions will likely determine the choice of the system. A snow production system that functions well in marginal conditions will be relatively expensive to install and to operate. There are many provers in the marketplace, and it is important to thoroughly evaluate which system provides the best overall production. If the snow production mainly takes place in marginal weather conditions, the choice of system may be simpler.

Building and installation

After the tender has been awarded, the actual building and installation can start (an eventual water concession, although it sometimes takes time, should be awarded before any ground work starts).  The on-site work should be led by a project coordinator, who organizes weekly construction meetings and safety controls, writes protocols, creates and adjusts the schedules, etc. 

The chosen contractor will establish themselves on the site, and must ensure the workplace safety, hold regular safety inspections and in general make sure safety is considered for workers as well as for public or visitors in the area (good signage is important).   Normally a fenced area for parking, construction trailers and equipment will be required. A snow making system consists of many expensive parts that also need to be protected (pipes, pits, valves, hydrants, fan guns, power- and data cables, tools, etc)

During the installation, the pipes should be pressure tested to avoid discovering problems after the pipes and ditches are covered. Valves and power connections are usually accessible in the pits or distribution boxes, and can be tested at any time.   

Towards the end of the construction process, it is important to have planned the steps for the comissioning of the system and the “hand-over” to the venue owner or ski club. All installed parts of the system must be reviewed and checked, and initial training and start-up of the system must be planned (and done) together with the system supplier. The electrical components, pumps, valves, hydrants, production units and the automation software must all be parts of a detailed check-list.   It is also important to ensure that a sufficient warranty period is in place for all the main components (3 year warranty is quite standard).  

Specific advice for Cross-Country/Biathlon systems

To sustain or possibly expand the current level of Cross-Country skiing and Biathlon in the future, it will be necessary to install more snow production systems at existing and new venues.  These systems are unique from systems used at alpine, snow parks and ski jumps since the courses and therefore the water (and air) pipes follow undulating terrain.  This requires some customization.

If the water pipes are installed above the frost line, it is important to make sure the water in the pipes drains when not in use, with pits for drainage at low points as well a air vents at high points. Pipes and cables must be installed according to the national code (see photos above) – with sand protecting the pipes, warning tape above the cables etc. such that the system will last for many years, and can safely be repaired if needed.

The work must be quality controlled along the way. For example, it is important to place the hydrants, pits and distribution boxes such that they will not cause any safety issues for skiers or the grooming machine operator.  All above-ground elements must be placed outside the ski trail as well as away from where an unlucky skier may crash and slide (for example, hydrants should be placed on the inside of downhill corners and not on the outside where a skier will naturally slide if out of control).  

It is also important that ditches, trails and side slopes are smoothened out with a back-hoe such that the soil edges are predictable for the grooming machine operator in the winter (an unnatural edge may ruin the snow surface with soil or gravel if the grooming machine blade “finds” it). 

On the Cross-Country/Biathlon stadium it is important that the hydrants are placed around the perimeter and not in the middle (where they always will be in the way of grooming and skiing). Since the area in the middle of the biathlon shooting range also needs to be snow covered, it is important to remember to place a hydrant nearby.

A stadium is often used as a snow depot during early season (since it is easy to create large piles of snow in an open, flat area), and later transported out on the courses. It is an advantage if the surface is paved (with a sligh 1 – 2 % gradience for drainage) such that gravel or dirt is not mixed into the snow when dozed into trailers for transportation and distribution. 

When deciding the detailed placement of the hydrants and the production units, it is important to consider the normal wind direction. Fan guns and lances should be placed such that the snow is produced and blown with the wind.

  • Placing the hydrant at the correct side of the trail is important, since otherwise the snowmaking hoses may need to cross the trail and be in the way of both skiers and snowmobile/machines
  • Hydrants and production units should be placed above the trail (uphill side) if possible such that the snow can blow a longer distance

Specific advice for alpine systems

Snow production systems for alpine venues are normally planned, designed and constructed by established and commercial ski resorts, although a few small alpine venues are operated by municipalities in certain countries (for example Norway). Large automatic systems are usually designed by resort planning- or engineering companies in cooperation with large snow production component providers. However, some smaller or medium-sized alpine venues may still consider planning expansions or new snowmaking areas on their own, and gathering good advice might be a smart investment. 

  • Correct placement of the fan guns or snow lances will considerably reduce the need for grooming machine work less pushing of snow
  • It is important to consider the normal wind directions and local conditions (ask local residents) before deciding where to install the snowmaking pipes, hydrants and producion units. Cold winds normally come from the north and follow the valley bottoms.
  • If the snowmaking pipes, hydrants and fan guns/snow lances are installed in the wrong location, the wind may blow the snow backwards and bury the fan guns/lances. Portable fan guns then need to be pulled far out onto the slopes and will require extra long hoses and power cords, as well as additional labour. The production will be slowed down, especially in the case of permanent fan guns or snow lances. 
  • Portable fan guns should be placed such that they can be moved backwards and up the hill without burying the hoses and the gun itself (with the produced snow). It is important to avoid moving the fan gun to an area that is newly snow covered (the figure below illustrates how a fan guns should be used and moved).

  • Permanent fan guns and snow lances require minimum hoses and will not be obstructive, however, they will only produce snow close to their position and may create lots of work with the grooming machines if the slopes are wide
    • by needing to push the snow across the slope to cover the whole ski course
  • A fan gun/snow lance installed on a tower will increase the snow production since the water droplets will have more time to freeze  
  • The distance between each of the hydrants and fan guns/lances should be adjusted according to the width and steepness of the hill, and according to the estimated hours the temperature is condusive for snow production
  • Hydrants and fan guns/snow lances should be aligned with other technical installations (light towers, etc) to reduce the number of obstructions for skiers
  • Ensure that the snow does not land on power lines, lift installations, buildings or other structures that may be damaged by the weight of the snow
  • Local and residential noise restrictions may affect the choice of placement, the hours available for production and even the chosen model of fan gun (some are more quiet than others).  
  • Portable fan guns must be anchored in place to avoid movement due to the forces during operation; this is especially important in steep terrain.  

Specific advice for Snow Parks 

Most venues with a Snow Park require an extra high capacity snow production system due to all the elements that are being built by snow.   

The systems needed at the snow parks are standard production units, but the planning and placement of hydrants and permanent fan gun/snow lances are a bit unique.

  • A snow park does not require equal capacity its entire length, so the hydrants and fan gun/snow lances should be placed where the demand is high and such that the snow production is finished at the same time in the different part of the course 
  • Flat sections planned for small elements, such as rails and boxes need less snow than steeper section used for jumps. Sections with uneven ground or with sideslopes need more snow than where the course follows the fall line.
  • The elements are often built on both sides of the course, so the pipes and hydrants should enable this. The elements require large amounts of snow, and the grooming operators would want to minimize the amount of time spent on moving the snow in place.
  • Always place the hydrant or fan gun/snow lance where the snow is easily acessible for the grooming machine, and near where the elements are planned. It is also best if the snow can be pushed downhill towards the elements. If any elements are built by soil, the hydrants should be placed a bit above the element, or in the middle of two elements if they are aligned. This makes it simple for the grooming operators to access the snow and push the snow downhill. In this way, the snow production can also take place during the season if needed.
  • Ses KUD/Norwegian Ski Federation manual https://snowpark.no/bygge-elementer/ for more details and videos.

Specific advice for Ski Jumps

Ski jumps are relatively similar and can therefore have a fairly standard snowmaking system design. It is foremost the landing hill and outrun that require snow. Since the landing hill is so steep, permanent snow lances are normally installed, while fan guns are often used on the outrun. The lances are placed evenly down the landing hill (starting on the knoll), and “with” the wind such that the snow blows onto the hill. On the outrun, fan guns are used since they have a larger capacity than snow lances (1 – 2 snow fans can produce enough snow in a short time).  Hydrants and power boxes must be placed outside the outrun perimeter safety fence to avoid any accidents.