The Municipality is worried that the canal and support boats might pollute the air with their diesel engines. Since the Municipality wants to create ideal conditions for the swimmers so that they can set records, we need to see if their concern is warranted and what should or could be done to improve conditions. Amsterdam also wants to advertise this event as a Neutral Energy Event (NEE).
Here we list some key information in regards to how we tackled the problem of planning such event. The following chart presents the key elements to know, their sources and their formats.
#
Parameter
Summary
Source
Format
1.
Quantity of diesel/fossil fuel boats vs electric
-550 canal boats (commercial), 75% emissions free (2020) these boats are used a lot, each boat up to 14 hours per day; 12,000 recreational boats, 5% emissions free (2020)
Originally from 1 Jan 2025, only electric boats will be allowed in Amsterdam’s canals, except the throughway. The deadline has been extended for pleasure boats due to complaints about insufficient charging infrastructure, which have been delayed due to pandemic. Currently 400-500 yachts have switched to electric, but there are only 24 16A shore power outlets.
Building new electric canal boat: 1m euros; Converting existing canal boat to electrical: 50,000 euros; Converting recreational boats to electrical: 4,000 – 40,000 euros depending on size; nstallation chargers: 100 boat charging stations installed by end 2021 + floating charging station by Skoon Energy to help with grid balancing
Minimising exposure to pollution from diesel/fossil fuel driven boats
No. of diesel/fossil fuel driven canal boats
As of 2020, there are about 12 550 boats in the canals of Amsterdam, approximately 550 of which are commercial boats, the remaining 12000 are recreational boats. Of the commercial fleet about 75% is emission free, while for recreational boats this percentage is only 5%. (Sterling 2020)
Type
No. of boats
% of boats that are emission free
Commercial
550
75
Recreational
12550
5
com_boats =550rec_boats =12550perc_com_boats_emission_free =75perc_rec_boats_emission_free =5com_boats_emission_free = com_boats * (perc_com_boats_emission_free /100)rec_boats_emission_free = rec_boats * (perc_rec_boats_emission_free /100)boats_emission_free = com_boats_emission_free + rec_boats_emission_freeboats_emission = com_boats + rec_boats - boats_emission_freeprint("The number of emission free boats is", int(boats_emission_free))print("The number of boats with emission is", int(boats_emission))
The number of emission free boats is 1040
The number of boats with emission is 12060
Peak times for canal boats
To create ideal conditions for the swimmers, we look towards hosting the event outside of ‘rush hours’ on the canals, to minimise impact of pollution from boats. This would also help ensure the continuity of boat traffic.
As can be seen in the figure below (Snelder, Minderhoud, and Calvert 2013) (no raw data available), the busiest hours on the water usually start around 15:00. For that reason the swimming event should be finished before 15:00.
image
To determine the ideal start time of the race, we consider the following:
People swim at speeds of about 8 km/h. (Thornton 2019)
Required length of the swim route is 5km.
For safety reasons, each wave of swimmers should have a maximum of 120 swimmers in the group. (Triathlon n.d.)
We plan for around 3000 swimmers for the swim meet, similar to the Amsterdam City Swim. (Swim n.d.)
length_of_route =5000# in metersnum_swimmers_per_wave =120num_swimmers =3000speed_swimmers_kmh =8time_between_waves =20# minutesspeed_swimmers_ms = speed_swimmers_kmh *1000/ (60*60)num_waves = num_swimmers / num_swimmers_per_wavesec_per_wave = length_of_route / speed_swimmers_msmin_per_wave = sec_per_wave /60duration_swim_min = min_per_wave + (num_waves * time_between_waves)duration_swim_hours = duration_swim_min /60end_time =15.00start_time = end_time - duration_swim_hoursprint("The start time for the first wave of swimmers is {}:00" .format(int(start_time)))
The start time for the first wave of swimmers is 6:00
Thus, the first wave of the race starts at 6:00 am with a next wave going every 20 minutes, this way the last wave will be out of the water by 15:00.
Energy use of boats
Energy requirements for canal boats in general
Energy use of canal boats compared to driving a car
Let’s say 10 boats are needed to assist in the city swim, we can calculate how many car-kM’s could be driven as equivalent to the power usage of boats. (Weerd 2023)(marina 2023)
yearly_car_consumption_kWh =7700hours_boat_race =9boat_diesel_usage =1# litre per hournum_boats =10energy_density_diesel =45# MJ/kgconversion_rate_MJ_kWh =0.277778# 1 MJ = 0.277778 kWhweight_diesel =0.84# kgkilos_diesel_per_boat = boat_diesel_usage * weight_diesel * hours_boat_racetotal_kilos_diesel_used = num_boats * kilos_diesel_per_boatenergy_use_boats_MJkg = total_kilos_diesel_used * energy_density_dieselenergy_use_boats_kWh = energy_use_boats_MJkg * conversion_rate_MJ_kWhdaily_car_consumption_kWh = yearly_car_consumption_kWh /365num_days_car_equivalent = energy_use_boats_kWh / daily_car_consumption_kWhprint("The energy use of 10 boats during the city swim is equal to the ""average car energy consumption in {:.1f} days." .format(num_days_car_equivalent))
The energy use of 10 boats during the city swim is equal to the average car energy consumption in 44.8 days.
Economic feasibility of switching canal boats to clean energy
Cost of converting boats to electric: (Sterling 2020)
Building new electric canal boat: 1m euros;
Converting existing canal boat to electrical: 50,000 euros;
Converting recreational boats to electrical: 4,000 – 40,000 euros depending on size;
Installation chargers: 100 boat charging stations installed by end 2021 + floating charging station by Skoon Energy to help with grid balancing
The feasibility of electrifying the entire fleet of Amsterdam is completely reliant on the willingness of businesses, private owners and the municipality to invest these amounts of money.
Energy requirements for support boats for the event
Number of support boats required
Drawing on other event data, here we list guidelines and recommendations taken by other organizers in Open Swimming competitions worldwide.
#
Parameter
Summary
Source
Format
1.
Open Water Swimming Manual 2022
“There must be sufficient safety craft or escort craft located on the course to immediately recognize when a swimmer is in distress and to initiate an immediate rescue response after observation or notification that a swimmer’s rescue is required.
British Triathlon Open Water Swiming Safety Guidelines
“Safety cover, safety craft and / or canoes must be provided on the water. Personnel assigned to water safety must be in the ratio of 1 to, at most, every 20 competitors. Emergency exit points should be available for swimmers to leave the water and separate exit points should be available for safety craft.”
The safety of all swimmers must be ensured during the whole duration of the race. During the event safety measures consist of:
Lifeguards in canoes;
As advised by the Open Water Swimming Safety Guide for Multi-Sport Events from the British Triathlon organisation boats should be in the water to be able to rescue swimmers in distress. A ratio of a minimum of one boat per twenty swimmers is advised in waters where shorelines are easily reachable. A swimmer should also always be within 50 meters range of a lifeguard. (Triathlon n.d.) Since most of the chosen route goes through canals it is deemed unsafe to have boats sailing so close alongside the swimmers. For that reason, lifeguards will be present every 50 meters in canoes instead of on boats.
This also contributes to the sustainability of the event. As mentioned previously, diesel engine boats are highly polluting and the resultant water toxicity can remain in the water for up to 14 days after the use of boats (Jüttner et al. 1995), so no fossil fuel boats should be used as support boats.
Safety platforms in the water;
To make sure distressed swimmers can easily leave the water platforms are placed every 100m alongside the swimming route where quay walls make exiting the water difficult.
No. of lifeguard canoes required = max(6.0, 100.0) = 100.0
Knowing that canals are too narrow for boats to navigate safely with swimmers around, lifeguards alongside the canals, along with platforms every 100m where quay walls are steep would suffice.
Energy requirements for support boats
100 canoes are used for the safety of swimmers, by using canoes instead of electric boats a lot of greenhouse gas emission is prevented. If we were to use electric boats electricity would have been used. Exactly how much energy we are saving by using canoes is calculated below.
num_canoes =100power_per_boat_kwh =20support_boats_power_use = num_canoes * power_per_boat_kwh * duration_swim_hoursprint("Reduced power use of boats: {:.2f} kWh".format(support_boats_power_use))
Reduced power use of boats: 17916.67 kWh
Solar panels required
Assuming that solar panels would be rented and installed for a week to power the boats the amount of solar panels needed is calculated below. Numbers about efficiency of solar panels are found at (Voltasolar 2023).
watt_peak =365# power of solar panel in the most ideal conditionsconversion_factor =0.85# based on amt and intensity of Netherlands sunlightsolar_panel_kWh_year = watt_peak * conversion_factorsolar_panel_kWh_week = solar_panel_kWh_year /52num_solar_panels_needed = support_boats_power_use / solar_panel_kWh_weekprint('Number of solar panels needed:', int(num_solar_panels_needed) +1)
Number of solar panels needed: 3003
If the city were to actually use electrified boats the solar panels that are needed to harvest the energy could be placed on the water. (floatingsolar 2023) has a circular system that floats. The size of the floating solar field is calculated below.
import matharea_of_solar_panel =1.65area_circle = num_solar_panels_needed * area_of_solar_panel# surface = pi * r^2r = math.sqrt(area_circle / math.pi)diameter =2* rprint("The diameter of the floating solar panels is {:.2f} m".format(diameter))
The diameter of the floating solar panels is 79.43 m
The circle needs to have a diameter of about 80m, this fits in the water close to the marine terrain as shown on the picture below.
diameter solar.JPG
Pollution impact of boats
Due to the lack of exhaust gas treatment systems in boat engines, as found in all modern car engines, a modern 5 horsepower 4-stroke outboard engine can be as polluting as 39 passenger cars driving at 95 km/h. (Propel 2022) While we do not know the detailed relationship between boat traffic and water quality, we do know that water toxicity as a result of fossil fuelled boats can stay present up to 14 days after the use of boats (Jüttner et al. 1995).
As such, water quality should improve if there are fewer or no canal boats using fossil fuels for at least two weeks prior to the event.
Conclusion
The swim meet is proposed to be conducted from 06:00 to 15:00 pm, with the following route:
Snelder, Maaike, Michiel Minderhoud, and Simeon Calvert. 2013. “Op de Amsterdamse Grachten, Hebben Wij Nu de Drukte in de Hand, Amsterdam ...” November.
