30-year Life Cycle Research Articles

Carbon Emission Accounting and Reduction Evaluation in Sponge City Residential Areas

This paper aims to establish a more standardized and regulated carbon emission accounting model for sponge cities by unifying the accounting content for carbon emissions and clarifying the relationships between carbon reduction benefits, carbon reduction effects, and carbon sequestration, in order to evaluate the carbon reduction outcomes and mechanisms of sponge city construction. Based on a Life Cycle Assessment (LCA) carbon emission accounting model using the carbon emission factor method, a newly constructed residential area in Tianshui City, Gansu Province, was selected as a case study, and the carbon emission reduction effect of sponge city construction was then investigated. Results indicated that the 30-year full life cycle carbon emissions for sponge city construction in the newly constructed residential area amounted to 828.98 tons, compared to 744.28 tons of CO2 reduction in traditional construction, representing a 47.31% reduction in carbon emissions. Over a 30-year life cycle, this equated to a total carbon emission reduction effect of 1460.31 tons. Additionally, under various rainfall scenarios in a typical year, the carbon emission reduction effect of sponge city construction exceeded the carbon emissions, achieving carbon neutrality within 22 to 30 years of operation. This demonstrates that the carbon emission reduction effect of sponge city communities is significant. The findings of this study provide data and a theoretical basis for the low-carbon construction of sponge cities in China.

Green energy and rooftop innovation: Unlocking the carbon reduction potential of photovoltaic-green roofs

As urbanization progresses rapidly, cities encounter significant environmental and energy challenges. Photovoltaic-Green Roof (PV-GR) technology offers an innovative strategy with the potential to alleviate urban carbon emissions and resource scarcity issues. However, the carbon reduction potential of PV-GR technology remains unclear. Hence, this study aims to comprehensively assess the carbon reduction potential of PV-GR. This is achieved by integrating Geographic Information Systems (GIS), lifecycle assessment, the Denitrification-Decomposition Model (DNDC), and solar simulation. Using Fuzhou City as a case study, the research indicates: (1) Fuzhou has approximately 72.9 km2 of rooftops suitable for PV-GR development, with an annual biomass production from herbaceous plants estimated at around 2.958 × 107 kg. The annual electricity production under the baseline scenario reaches 9,678 GWh, satisfying about 17 % of Fuzhou’s annual electricity demand. Moreover, in an optimistic scenario, electricity generation rises to 10,176 GWh, and even in a pessimistic scenario, it could achieve 9,471 GWh. (2) In the baseline scenario, Fuzhou’s PV-GR annual carbon reduction is estimated at 6.678 × 106 t CO2, potentially offsetting about 11.14 % of the city’s annual carbon emissions. In an optimistic scenario, this reduction increases to 7.022 × 106 t CO2, and even in a pessimistic scenario, the reduction remains significant at 6.535 × 106 t CO2. (3) Over a 30-year lifecycle, the carbon emissions from PV-GR are projected to total 3.092 × 107 t CO2, accounting for 51.34 % of Fuzhou’s annual emissions. In an ideal baseline scenario, the net carbon reduction over the lifecycle of PV-GR could total 1.703×108 t CO2, effectively offsetting 282.76 % of Fuzhou’s annual carbon emissions. Additionally, scenario simulations suggest that by 2030, potential electricity generation from PV-GR could increase to between 10,463 GWh and 10,901 GWh, due to changes in power structure and urban expansion. Overall, this study demonstrates that PV-GR holds considerable potential for carbon reduction.

LPG, Gasoline, and Diesel Engines for Small Marine Vessels: A Comparative Analysis of Eco-Friendliness and Economic Feasibility

As an escalating global concern for environmentally sustainable marine fuels, liquefied petroleum gas (LPG) is attracting attention as an eco-friendly and economical alternative. This study explored LPG utilization in small marine vessels, focusing on its eco-friendliness and economic feasibility. To assess its environmental implications, the AVL FIRE simulation program was used to compare CO2, CO, NO, and soot emissions from LPG engines with those from conventional gasoline and diesel engines. The LPG engine model relied on data from a pioneering type-approved experimental LPG engine designed for small South Korean marine vessels, while parameters for gasoline and diesel engines were adjusted to suit their distinctive features. Regarding long-term economic feasibility, assuming a 30-year ship lifespan, incorporating 2022 annual average prices, average annual price growth rates, and annual fuel consumption data of each fuel, results indicate that LPG engines exhibited lower CO2, CO, NO, and soot emissions than conventional engines, except that NO emissions were higher than gasoline engines. Evaluating LPG’s economic feasibility over a 30-year ship life cycle for an individual vessel revealed varying fuel cost savings, with the greatest savings observed in gasoline–other (KRW 2220.7 million) and the least in gasoline–coastal (KRW 1152.5 million). These findings offer vital insights for ship operators and policymakers seeking a balance between eco-friendliness and cost-effectiveness, as well as LPG engine technology emerging as pivotal for a sustainable future, harmonizing environmental protection and economic viability.

Catchment-scale life cycle impacts of green infrastructures and sensitivity to runoff coefficient with stormwater modelling

Urban green infrastructure (GI) has been widely used in sponge city construction to manage hydrological processes. While studies on environmental benefits of GI from the perspective of whole life cycle assessment (LCA) have been reported in recent years, few have explored and compared the environmental performance of different GIs within a single catchment, which is directly linked to catchment-scale hydrological control. This study focuses on a Sponge City pilot project in Shenzhen, China, including three typical types of GI: permeable pavement, green roof, and sunken green space. By collecting hydrological data, land use, and life cycle inventory of GI and employing SWMM (Storm Water Management Model)-based stormwater modelling, we have revealed the environmental impacts at different stages of the life cycle of the GI scenario and three GIs through comparative and sensitivity analyses. Notably, we have disclosed, for the first time, the effect of the runoff coefficient in LCA. Our findings indicate that over the 30-year life cycle, the total environmental impact of the GI scenario is 24 % smaller than that of the hypothetical grey scenario. Permeable pavement exhibits the largest environmental impact per unit area, being 1.8 times and 7.6 times greater than that of the green roof and sunken green space, respectively. The operation stage of the three GIs significantly mitigates eutrophication and climate change. Furthermore, sensitivity analysis demonstrates that an increase in surface runoff undermines the environmental benefits of GIs. These results highlight the importance of embedding stormwater modelling into LCA, enabling catchment-scale integrated evaluation and equivalent assessment of different GIs within a single catchment whereby the influence of external factors such as climate change can be described, which aids in understanding the dynamic environmental performance of GIs. The proposed research framework and results are anticipated to provide valuable guidance for future GI construction and carbon-neutral policies.

Life cycle assessment and life cycle cost analysis of anion exchange and granular activated carbon systems for remediation of groundwater contaminated by per- and polyfluoroalkyl substances (PFASs).

Anion exchange resin (AER) and granular activated carbon (GAC) have emerged as prominent technologies for treatment of waters contaminated with per- and polyfluoroalkyl substances (PFASs). This study compares the life cycle environmental impacts and life cycle costs of remediating PFAS-contaminated groundwater with these competing technologies, using field pilot data to inform model inputs. Comparative analysis indicates that AER systems employing single-use "PFAS-selective" resins have lower environmental impacts and costs than systems using regenerable resins or GAC adsorbents, supporting its use in future remediation efforts. Use of GAC operated as a single-use adsorbent led to the highest emissions as well as the highest treatment costs, with thermally-reactivated GAC proving to be less impactful than regenerable AER treatment. Sensitivity analyses highlighted the dominance of media usage rate (MUR), which is highly dependent on the selected PFAS treatment goals, to determine environmental impacts and costs over a 30-year system life cycle. Selection of very stringent changeout criteria (e.g., detection of any PFASs in effluent) significantly reduces the advantages of single-use resins. For regenerable AER, environmental impacts were dominated by management of the PFAS-contaminated brine/co-solvent waste stream used to regenerate the adsorbent, as well as the cosolvent content of the regenerant mixture and the cosolvent recovery efficiency achieved via on-site distillation. High impacts estimated for GAC adsorption, the result of high MUR relative to ion exchange media, can be significantly reduced if spent adsorbents are reused after thermal reactivation, but impacts are still greater than those predicted for single-use ion exchange systems. Findings are expected to hold across a range of diverse sites, including drinking water systems treating more dilute sources of PFAS contamination, as PFAS breakthrough was not found to be highly sensitive to sourcewater PFAS concentrations.

Offshore floating photovoltaic system energy returns assessment—A life cycle energy analysis-based perspective

<abstract> <p>Researchers have long regarded photovoltaics (PV) as a poor energy return (ER) compared to fossil fuels. Although the latter's energy-return-on-investment (EROI), like oil, coal, and gas, are above 25:1 at the primary, they are about 6:1 at the final stage. Following the technology creation, it is essential to investigate whether the solar module technology innovation affects the ER. Much literature delivers the ERs of fossil fuels and PV. However, it does not address the life cycle analysis or life cycle energy analysis (LCEA) assessments. This paper, employing time-series and LCEA analyses, performs an ER evaluation of the 181-MWp global most extensive offshore floating PV (OFPV) in a 30-year life cycle at Changhua Coastal Industrial Park, Taiwan. The results show that the energy payback time (EPBT) is about one year. The EROI is about 29.8, which is superior or complies with the upper limits of previous studies under the same insolation. The approach proposed in this study should help future PV stations' ER analysis and clarify whether the innovation benefits from improving the system's performance. The results also assist in investors' decision-making regarding deploying PV projects in the future.</p> </abstract>

Economic analysis of a zero-carbon liquefied hydrogen tanker ship

The green hydrogen economy is considered one of the sustainable solutions to mitigate climate change. This study provides an economic analysis of a novel liquified hydrogen (LH2) tanker fuelled by hydrogen with a total capacity of ∼280,000 m3 of liquified hydrogen named ‘JAMILA’. An established economic method was applied to investigate the economic feasibility of the JAMILA ship as a contribution to the future zero-emission target. The systematic economic evaluation determined the net present value of the LH2 tanker, internal rate of return, payback period, and economic value added to support and encourage shipyards and the industrial sector in general. The results indicate that the implementation of the LH2 tanker ship can cover the capital cost of the ship within no more than 2.5 years, which represents 8.3% of the assumed 30-year operational life cycle of the project in the best maritime shipping prices conditions and 6 years in the worst-case shipping marine economic conditions. Therefore, the assessment of the economic results shows that the LH2 tankers may be a worthwhile contribution to the green hydrogen economy.

Appraising the life cycle costs of heating alternatives for an affordable low carbon retirement development

This paper assesses the low carbon design of housing developments for retired people who are willing to downsize. There is a need for a strategic approach to provide energy-efficient housing in general, but specifically for a growing aged population. This approach should be inclusive and affordable. Therefore, this study assessed the capital and operational costs of space and water heating of typical UK retirement dwellings by considering over a 30-year life cycle, the use, maintainability, replacement frequency, and sustainability of applying different low carbon energy technologies and renewables to various primary heating plants. Conventional heating systems (e.g. gas, electricity) and low carbon green technologies, such as photovoltaics (PV), solar hot water systems (SHW), combined heat and power (CHP) and air source heat pumps (ASHP), were studied and compared. A combination of ASHP and a SHW system reduced the energy costs by 57% maintenance costs by 14% and produced 46% lower carbon emissions than the gas boiler option. However, the ASHP option generated 75% more capital costs than the gas boiler scenarios as well as high replacement costs due to the short life expectancy of the system. The gas boiler and PV combination had the lowest capital, energy, and life cycle costs but also hadhigh carbon emissions. The results suggest that UK government incentives, such asapplying a carbon tax would significantly reduce the payback time of green technologies and could, therefore, be the key drivers of low carbon adoption.

Energy and cost efficiency of phase change materials integrated in building envelopes under Tunisia Mediterranean climate

An extensive study, including energy and economic analyses has been proposed to assess the benefits of the phase change materials (PCMs) when integrated into building envelopes under the Tunisian climate. Sensitivity analyses have been presented in order to investigate the PCM interaction with the thermal insulation and the cool roof measures. Numerical simulations with EnergyPlus highlighted the crucial selection of an optimal phase change temperature. The PCM applied on the outside face of a brick wall provided better energy efficiency, with the highest energy savings up to 13.4% achieved for the south orientation. The integration of the PCM improved the thermal inertia of the wall with an increase of 2 h in the time lag for the east orientation. A 30-year life cycle cost analysis showed that the integration of the PCM in a brick wall is not cost-effective. The interaction between the PCM and the thermal insulation in a brick wall showed a better efficiency of the PCM in the absence of insulation, providing the highest rate of energy consumption reduction, estimated to 12.21%. The integration of the PCM in a concrete-based cool roof compensated the wintertime penalties and reduced the daily surface temperature fluctuation by up to 5.35 °C.

Incorporating Dynamic Traffic Distribution into Pavement Maintenance Optimization Model

An optimal pavement maintenance strategy can keep the pavement performance at a high level under budget constraint. However, the impact of changes in traffic distribution caused by maintenance actions on user costs is rarely investigated in existing approaches. This research aims to solve the optimization of pavement maintenance strategy using a multi-stage dynamic programming model combined with the stochastic user equilibrium model, which can simulate the dynamic traffic distribution in the life cycle. To deal with the proposed model, a heuristic iterative algorithm is put forward. Ultimately, a hypothetical network is established to test the model and algorithm. The testing results prove that the proposed framework has an advantage in assessing user costs comprehensively and can provide an effective and optimal pavement maintenance strategy in a 30-year life cycle, which improves the efficiency of budget and pavement conditions. Additionally, this research provides quantitative evidence of interdependency in a road network, i.e., pavement maintenance actions on links can interfere with the user costs and traffic flow distribution in the whole network, which should be taken into account in pavement maintenance decision-making.

Effects of a Green Roof on Stormwater Regulation and Cost-benefit Analysis

Increasingly frequent urban waterlogging disasters, which are mainly caused by the increase in impervious surfaces due to rapid urbanization, have attracted public attention. Green roofs are conducive to increasing the urban pervious surface area to control sources of runoff, which has great significance for the ecological environment. This study uses the green roof of the administrative building of Jinling Primary School in Nanjing as the study area. 76 rainfall-runoff events collected over 17 months (2016-06-2017-10) were used to calculate the comprehensive runoff control ability and factors influencing the green roof in the context of the site scale. Based on life cycle assessment theory, the benefits of stormwater regulation over its 30-year life cycle were quantitatively evaluated. The results show that:① The average retention of the green roof was 62.7%, which could have a significant impact on runoff and peak flow, reducing the runoff time and delaying the flood peak. ② The green roof has a strong ability to retain runoff during small and medium rainfall; however, this ability becomes low when the retention capacity is saturated or not fully recovered, even in small rainfall-runoff events. ③ The main factors affecting the retention ability of the green roof are the total rainfall, rainfall intensity, and water content of the growth substrate soil. ④ The green roof has great economic benefits, with a construction cost of about 12.51 yuan·m-3 and a return on investment of 0.41. The results of this study can provide an important scientific basis and decision-making reference for the planning and construction of green roofs and the promotion of related policies.

Life cycle production and costs of a residential solar hot water and grid-connected photovoltaic system in humid subtropical Texas

Hot and humid climates with high solar radiation have the potential to offset residential building energy consumption with the application of solar hot water and photovoltaic electricity generation. However, costs, lack of incentives for the systems, and the need for proof-of-concepts continue to limit market penetration. The surplus of natural gas in certain areas of the United States, particularly Texas, continues to keep gas and electricity production economical compared to solar alternatives. However, trends that demand lower energy homes, a desire for local energy independence, and the lowering of carbon dioxide emissions continue to fuel solar energy systems penetration. To support solar use, this research was performed to evaluate and analyze the real-world life cycle energy and costs of a solar photovoltaic and solar hot water system (SHWS) installed on a high-end residential home in Houston, TX (IECC Zone 2). The house was a well-insulated, large urban home with two renewable energy systems installed: a 3.5 kW solar photovoltaic system (SPVS) and a 1.71 kW solar hot water system. Analyses were part of a larger study performed to investigate the contributions of the solar energy offsets on the operational energy of the building over a life cycle period of 30-years. Field measurements of energy production were compared to solar energy simulations based on the typical meteorological year and the National Solar Radiation Database (NSRDB) data. NSRDB provided the basis for a probabilistic interpretation of annual energy production in terms of probability measures, P50/P90. It was found that field estimates were within simulation uncertainties and P90 predictions were within 2.5% of TMY3 (typical meteorological year data 3) results for both the solar photovoltaic system (SPVS) and solar hot water system (SHWS). Additionally, optimizations in the system design and life cycle costs were investigated to determine the annual optimal performance for the solar energy systems. The SHWS was installed at a less than optimum azimuth of 270° instead of 180° (corresponding to a 16% reduction in annual output). The SPVS was installed at optimal design conditions of 180° azimuth and 42° tilt. Payback and levelized cost of energy (LCOE) could have been minimized with the addition of another solar hot water collector with a minimal impact to overall cost. Cost sensitivity analysis on the LCOE and net-present value (NPV) were also performed and over a 30-year life cycle period, TMY3 based simulations predicted a NPV of $796 (21.8-year non-discounted payback) and -$1246 (29.2-year non-discounted payback) for the SHWS and SPVS, respectively. The SHWS achieved a LCOE of 8.1 ¢/kWh, while the value for the SPVS was 12.29 ¢/kWh. For the SPVS, the photovoltaic module and collector costs were the largest life cycle costs, and of special note, a reduction in the module cost by 67% reduces the LCOE to the market average-high electricity price of 10 ¢/kWh. Finally, the combined renewable energy systems generated an estimated 30-year life-cycle energy production of 184 814 kWh, with auxiliary gas provided for supplemental hot-water heating. On average, a Texas residential home utilizes 420 000 kWh of electrical energy, 19% of which is domestic hot water demand.

The AMEDD Uses Goal Programming to Optimize Workforce Planning Decisions

The mission of the Army Medical Department (AMEDD) is to provide medical and healthcare delivery for the U.S. Army. Given the large number of medical specialties in the AMEDD, determining the appropriate number of hires and promotions for each medical specialty is a complex task. The AMEDD Personnel Proponency Directorate (APPD) previously used a manual approach to project the number of hires, promotions, and personnel inventory for each medical specialty across the AMEDD to support a 30-year life cycle. As a means of decision support to APPD, we proffer the objective force model (OFM) to optimize AMEDD workforce planning. We also employ a discrete-event simulation model to verify and validate the results. In this paper, we describe the OFM applied to the Medical Specialist Corps, one of the six officer corps in the AMEDD. The OFM permits better transparency of personnel for senior AMEDD decision makers, whereas effectively projecting the optimal number of officers to meet the demands of the current workforce structure. The OFM provides tremendous value to APPD in terms of time, requiring only seconds to solve rather than months; this enables APPD to conduct quick what-if analyses for decision support, which was impossible to do manually.

Stochastic evaluation of mortgage default losses resulting from flood damages and different mortgage arrangements for post-Katrina Louisiana houses

Purpose – The purpose of this paper is to investigate the total number of mortgage default occurrence possibilities and monetary damage amounts to the sampled properties due to the excessive flooding caused by natural disasters. Mortgage default loss assessments due to natural catastrophic events are of great interest to lenders, insurance firms, forensic engineering professionals, inspecting agencies and the federal and state government planning officials and risk-mitigating teams. Design/methodology/approach – In this study, a stochastic methodology is used to address the risk of mortgage default losses and the homeowners’ investment returns, given: damage severity levels of hurricane floods and the mortgage types and arrangements on selected properties. Nine different houses, with various mortgage arrangements, located in different flood damage zones were investigated three years after Hurricane Katrina. To quantify the flood damage risk values which are compared with exceeding damage probabilities, the Poisson’s distribution is used through performing random variable analysis walks for each property during each house’s mortgage life cycle. Findings – Henceforth, through introduction and constructing the “Zonal Damage Matrix” for the investigated houses, the total number of mortgage default occurrence possibilities and monetary damage amounts to the properties are calculated for each exceeding flood. Thereafter, the homeowners’ net equity values and the investment returns are estimated for risk identification and evaluation purposes. Originality/value – For each of the sampled houses, the probability of mortgage defaults and the homeowners’ net equity values are estimated using Poisson’s distribution based on 60,000 randomly generated numbers to construct ten different hazard-related default scenarios for each property over the 30-year mortgage life cycle. The investment returns are therefore estimated for risk identification and evaluation purposes.

The hydrologic and economic feasibility of micro hydropower upfitting and integration of existing low-head dams in the United States

The integration of hydropower facilities on existing low-head, non-Federal dams and their subsequent tie to regional electricity grids may serve as a useful de-centralized component of renewable energy integration in the United States. Thousands of low-head dams do not provide power and thus present few benefits with significant costs, including safety liability, fragmentation of river ecosystems, and persistent economic burden induced on state agencies due to regular inspection requirements. We conducted a feasibility study in the Piedmont region of North Carolina cataloguing over 1000 non-Federal dams with hydraulic head ranging from 4.6m to 10.7m (15ft to 35ft) and power capacity <300kW (“micro” hydropower). Generation potential, greenhouse gas reductions, and financial viability were refined for 49 low-head dams over a 30-year life cycle using industry standard software (RETScreen4). Results suggest that most of these dams are not financially viable for energy production under cost structures evaluated at the time of this study. However, our results indicate that some low-head dams may be viable for energy production if provided funding opportunities comparable to the concurrent wind and solar markets.

Woody biomass phytoremediation of contaminated brownfield land

Economic and environmental regeneration of post-industrial landscapes frequently involves some element of re-afforestation or tree planting. We report field trials that evaluate whether woody biomass production is compatible with managing residual trace element contamination in brownfield soils. Large-scale mapping of contamination showed a heterogenous dispersion of metals and arsenic, and highly localised within-site hotspots. Yields of Salix, Populus and Alnus were economically viable, showing that short-rotation coppice has a potentially valuable role in community forestry. Mass balance modelling demonstrated that phytoextraction potentially could reduce contamination hotspots of more mobile elements (Cd and Zn) within a 25–30-year life cycle of the crops. Cd and Zn in stems and foliage of Salix were 4–13 times higher than EDTA-extractable soil concentrations. Lability of other trace elements (As, Pb, Cu, Ni) was not increased 3 years after planting the coppice; woody biomass may provide an effective reduction of exposure (phytostabilisation) to these less mobile contaminants.

User cost savings in eliminating pavement excavations through employing trenchless technologies

When a pipeline is installed under flexible pavement structures using open excavation and fill methods, the excavation can result in premature pavement deterioration due to difficulties associated with trench site restoration and soil and asphalt compaction. In developed areas, trenchless construction methods have become a popular alternative to open trench excavation because of reduced surface disruptions and reinstatement costs, a shorter construction period, and significantly reduced traffic delay costs associated with construction by saving time in construction operations. This paper summarizes a recent study that examined how pipeline installations on 1- and 7-year-old Ontario municipal collectors and minor arterial roads impact the 30-year life cycle of a pavement in terms of performance, future maintenance costs, and user-delay costs. Study results indicated that (1) approximately 30% reduction in pavement life can be expected once an excavation is made in a road; (2) increased maintenance and rehabilitation costs for excavating 1-year-old pavement were determined to be approximately Can$146/m2, and the costs for excavating 7-year-old pavement vary from Can$85 to $140/m2; and (3) the use of trenchless technology with good construction practices has the potential to significantly reduce road maintenance and rehabilitation costs and user-delay costs.Key words: pavement performance, open excavation, trenchless technologies, user-delay costs.

LIFE CYCLE EVALUATION OF THE ENVIRONMENTAL LOADING AND CONSTRUCTION COST IN PAVING PROCESSES

舗装道路 (アスファルトおよびコンクリート) の建設と維持修繕に伴う環境負荷とコストについて, 様々な維持修繕モデルケース別に, 設計解析期間30年間にわたる LCI (Life Cycle Inventory) を初期建設段階と維持修繕段階に分けて集計し、環境負荷・コスト両面からみた道路舗装のライフサイクル評価を試みた. 建設・維持修繕いずれの段階においても, 再生材料の活用により環境負荷を最大40%程度削減できることがわかった. アスファルト舗装については, 維持修繕段階の占める割合が環境負荷・コストともに全体の40～50%となった. また, 打換え工事の少ない軽微な補修を繰り返す維持修繕モデルケースがすべての環境負荷項目・コストについて有利であった.

Shipboard Data Multiplex System—A Method of Reducing Shipboard Electrical Cable Requirements

A modern naval destroyer requires almost 183 000 m (60000 ft) of copper cable for information transfer between units of a given system or as interface connections between systems. Over a 30-year life cycle, the ship may undergo regular overhaul four times and an extensive modernization at least once. During each of these evolutions a large portion of the through-ship cabling installed for information transfer, data exchange or equipment control must be rerouted or replaced, at substantial cost. By multiplexing data exchange on a few coaxial cables, the Shipboard Data Multiplex System (SDMS) will replace or substantially reduce most through-ship signal cable requirements, and thus cost far less than a conventional fixed-wire installation. When reconfiguration is required at a later date, only changing short interface cables and inserting small Programable Read Only Memories (PROM's) into the multiplexers will be necessary. This paper outlines through-ship electrical cable requirements, wireway design and installation costs, and a comparison between SDMS and a conventional fixed-wire system for a major combatant.