gerald ROY spencer, P.E.




Gerald Spencer, P.E. has more than 50 years experience serving as the Engineer of Record responsible for the design and construction of the MEP portions of more than 1300 building construction projects since 1968 including more than 30 years of preparing forensic engineering reports. Gerald Spencer, P.E. has also been providing licensed professional engineering expert opinion and testimony concerning HVAC, electrical, plumbing, cryogenics, ventilation, construction contract compliance, construction cost  estimating, construction contract acquisition, construction contract administration, and other construction matters for attorneys with  since 2001.


CHARETTE DESIGN PROCESS


Gerald Spencer conducted the (Dec 94) the Charette design process for the addition to the Adahl Chapel at Kelly AFB, TX, the USAF New Joint Intelligence Systems Integration Facility at Lackland AFB, Texas and the (Jul 95) the Charette design process for the IAAFA Armory & Storage facility - Camp Bullis, TX. Gerald R. Spencer, PE has performed space planning and data processing equipment layout for many different data processing facilities, including the Cray V Super Computer Systems, the Amdahl Super Computer Systems, and the 400 hz IBM equipment that supports these systems. Gerald Spencer, PE (Jan 94) participated the Charette design process for the Fleet Mine Warfare Center at Ingleside NS, Texas. The Fleet Mine Warfare Center at Ingleside NS, Texas has classified controlled access area encircled with non-classified limited access areas, and non-classified areas for visitors.

ENVIRONMENTAL CONSIDERATIONS FOR ELECTRONIC EQUIPMENT


Gerald Roy Spencer, P.E. is the EOR for the construction of more than 40 raised floor data processing projects during the last 20 years, including seven projects totaling more than 75,000 SF of raised floor data processing equipment space in the last 5 years. The raised floor details generated by Spencer Engineers, Inc. (SEI) are now the site standards for raised computer floor construction at NASA-JSC. Most manufacturers installation details work, but there are sometimes better ways to install the raised floors. Handrail details to comply with codes are sometimes a structural problem. Projects include the Building 16 addition for celestial navigation training at NASA-JSC and the Shuttle Flight Simulator in building 16 at NASA-JSC. Gerald Roy Spencer, P.E. is also the AE of record for more than 10 telephone office projects that have the same environmental considerations.


Gerald Roy Spencer, P.E. has designed HVAC systems that control the relative humidity to within the limits specified for the equipment. The SW Bell telephone company leased computers from an un-named company with maintenance included in the lease charges. This computer company placed temperature/humidity recorders in the space, and then billed SW Bell for the maintenance when the humidity was not maintained within the specified limits. Gerald Roy Spencer, P.E. was retained to modify the HVAC system to maintain specified RH. Gerald Roy Spencer, P.E. is the EOR for many separate data processing room HVAC systems.


Gerald Roy Spencer, P.E. is the EOR for many electrical systems that support the data processing operations. Gerald Roy Spencer, P.E. has been employed by NASA and Warner Cable to solve complicated ground problems. Gerald Roy Spencer, P.E. has designed many built-up UPS systems for NASA and for the Telephone Company. Gerald Roy Spencer, P.E. is the AE of record for many power conditioning projects for NASA and EXXON. Gerald Roy Spencer, P.E. has been employed by NASA and EXXON to document and solve harmonic circulating current problems and transient surge problems with existing computer installations.


Gerald Roy Spencer, P.E. has designed modifications to all of the older data processing areas at NASA-JSC that will provide Emergency Power Off systems and other modifications in order to comply with current codes. SEI Architects and Engineers have many years experience modifying the Mission Control Center (MCC) Houston, and this expertise is available for this project.


data processing EXPERIENCE AND COMPLETED PROJECTS


The following is a partial list of data processing facilities where Spencer Engingeers, Inc. was the AE of record:


1.   U. S. AIR FORCE INTEGRATED INTELLIGENCE FACILITY - 2002 - LACKLAND AFB, TEXAS - 10,000 SF teaching/training facility plus 1500 SF Secure (SCIF) Data Processing Facility - Project No. MPYJ-03-3275 - Mr.Fred Mengdon - 210-671-1541 - Mr. Gerald R. Spencer, P.E., facilitated the charrette design conference to evaluate and re-affirm the design criteria, to create a concept plan, and to get approval of the concept plan from all of the concerned parties. Gerald Spencer, P.E., was the project director and also the mechanical and electrical designer for the mechanical and electrical infrastructure systems. Mr. Carl Talbot, AIA, Mr. Jim Dunaway, AIA and Mr. William A. Davis, RA, P.E. prepared the architectural contract drawings. Mr. W. Paul Jones, AIA was the specifications writer and hardware specialist for the architectural building items. Mr. John L. Elam performed the Civil Design and the Structural Design. The proposed facility will consist of a 8,000 sf building housing two highly technical areas and support areas. There will be an office - laboratory area with raised computer floor for data transmission media wiring and power connections. There will be an air conditioned high bay storage warehouse with positive temperature and humidity control to store temperature and humidity sensitive data processing hardware and equipment. SEI designed a pre-engineered insulated metal building with walls insulated to comply with the SCIF construction requirements for sound attenuation. This project was within a secure fenced area so that physical protection was provides by a security fence that enclosed this new site. This facility was constructed in an un-secure area and the security fence was relocated after construction to enclose this facility into the secure area. The foundation design was a fully supported structure above grade, and the floor between grade beams was slab-on-grade placed on top of 4 feet of select fill. Foundation piers were 45 feet deep. This project had raised computer flooring in the communications areas, secure grounding, separate secure power, separate un-secure power, electronic equipment repair/assembly laboratory, high bay equipment storage, restrooms, break room, and exterior security lighting. This project has masonry front walls and some windows that meet SCIF attenuation requirements. The metal wall panels with the 6" thick fiberglass insulation meet the SCIF requirements. The facility is fully air conditioned. LCCA indicated that electric heating was justified since the building was so well insulated, and the ventilation requirement was so low. The HVAC systems will consist of separate DX, split air conditioning heat pump systems and electrical resistance re-heat heating systems for positive humidity control. A separate system will supply each controlled-conditioned zone with separate heating, humidity control, and cooling as required to maintain room temperature. The majority of the HVAC requirement is internal load (people, computer, lighting). The building envelope is well insulated to a "U" value of 0.030 average. The building will have a pre-treated outside air system that will provide absolute control of the maximum relative humidity in the building except when the exterior doors are open for extended lengths of time. The AE recommends that the USAF minimize the time when exterior doors are open. The OSA delivery fan will be controlled by a C02 sensor in the common RA plenum on the equipment mezzanine. This will only introduce OSA to the building when the personnel need additional OSA for Indoor Air Quality Control, and/or for building pressurization when needed. There will not be any handicapped personnel at this facility, but the restrooms will be designed in accordance with the ADA handicapped accessibility requirements for possible future needs. It will be less expensive now to construct the restrooms for the handicapped now as compared to modifying (tearing down and re-constructing) the restrooms at a later date. Handicapped visitors are sometimes guests or awardees at change of command and/or award ceremonies. System will comply with the NFPA 13 in accordance with the requirements of NFPA 13-1996 for an Extra Hazard Group 1. 


2.   U S STATE DEPARTMENT - 2001 - U S CONSULATE MUMBAI (BOMBAY), INDIA - Provide remodel existing data processing equipment and provide new ups and auxiliary power generation to serve new data processing equipment.


3.   NASA-JSC - 1999 - EMERGENCY POWER UP-GRADE - Man Rated Space Chambers “A” & “B” Instrumentation and Control System - Increase the UPS power. 


4.   U S STATE DEPARTMENT - 2000 - U S EMBASSY NEW DELHI, INDIA - Provide study to provide new ups and auxiliary power source to serve new data. 


5.  U S NAVY - 1998 - ASRM TRAINING FACILITY - Corpus Christi NAS, TX - Helicopter electronic Simulator Mock-up for Mine Warfare Training. This project included fiber optic and twisted pair site data transmission media distribution system for data processing and communications between buildings. 27,000 SF teaching/training facility. SEI was consultant to Brown & Root, Inc. for MEP design.


6.   U S NAVY - 1997 - Hanger 42 - CORPUS CHRISTI NAS, TX - Project included a secure electronic data processing facility for communications.


7.   U S NAVY - I996 - INGLESIDE NAVAL STATION, TEXAS - FLEET MINE WARFARE CENTER - 87,000 SF teaching/training facility. SEI was consultant to Brown & Root, Inc. for space planning and for final MEP. 6,500 SF secure. 


8.   NASA-JSC - 1996 - REPLACE VACUUM CHAMBER OPERATING CONTROLS - Man Rated Space Chambers “A” & “B” Instrumentation and Control System with a new 15,000 point Distributed Control System (DCS) served by multiple host Central Processing Units (CPU), remote stand alone (PLC) control/communication modules, multiple remote I/O modules, and dual data transmission medium data highway.


9.    NASA-JSC - 1999 - DESIGN OF EMERGENCY POWER OFF SYSTEMS.  


10.  NASA-JSC - 1996 - REPAIR ELECTRICAL EQUIPMENT - BUILDINGS 13 &. 


11.  NASA-JSC - 1996 - BUILDING 30 - MISSION CONTROL CENTER - REPLACE 3.12. NASA-JSC - 1995 - BUILDING 30 - MISSION CONTROL CENTER UPS. 


13.  NASA-JSC - 1992 - BUILDING 16 - LAUNCH PROCESSING FACILITY - 3,000 SF computer facility expansion of existing data processing facility.


14. NASA-JSC - 1992 - BUILDING 5 - MODIFICATIONS TO CREW TRAINING - Added 2500 SF - 2,500 SF computer floor mezzanine addition for computer 3.15. NASA-JSC - 1992 - BUILDING 17 - CENTRAL AVIONICS / SOFTWARE FACILITY - Remodeled 24,000 SF of existing office space into data processing. 


16. EXXON COMPUTER CENTER POWER ANALYSIS - 1991 - Analyzed existing power with Dranitz 658 and prepared formal report documenting existing conditions before additional data processing equipment and SRC elevator controls.


17. NASA-JSC - 1992 - BUILDING 16 ADDITION - $1,650,000 - This project is an addition to the Avionics Test Facility for the addition of a space flight celestial navigation simulation trainer. This project is an addition to the Avionics Test Facility for the addition of a space flight celestial navigation space simulation trainer. 


18. NASA-JSC - 1990- BUILDING 16 - SAIL GROUNDING PROBLEM SOLVING - Field investigated and defined existing ground loops, harmonic circulations, and other electronic noise problems. Designed remedial corrections to minimize problems.


19. NASA-JSC - 1990 - BUILDING 5 - $450,000 - This project added a 1600 s.f. computer floor mezzanine around the existing SLS (Space Laboratory Simulator) to allow for the installation of additional computer equipment to serve the earth simulation of the tests before actual performance of the laboratory procedures.


20. NASA-JSC - 1990 - BUILDING 35 SMTF - $250,000 - This project added a 2500 s.f. computer floor to allow for the installation of additional computer equipment to serve the SMTF STEP 2/3 shuttle flight simulation/training operations.


21. EXXON-EPRC CRAY I COMPUTER INSTALLATION HOUSTON, TEXAS - 1984 - $1,400,000 - This project was to install a new CRAY I Super computer into the existing facility. This project included the design of a 400 Hertz Power generation and distribution system to serve the $28,000,000 owner furnished Cray I Computer. Gerald Roy Spencer, P.E. designed an emergency power system to serve.


22. EXXON-EPRC CRAY V COMPUTER INSTALLATION HOUSTON, TEXAS - 1991 - $1,100,000 - 16,000 SF Data Processing Room - This project was to install a new CRAY V Super computer into the existing facility. Amdahl and IBM 400 Hertz equipment was also installed to feed the CRAY V computer. This project included the design of a 400 Hertz Power generation/distribution system, the chilled water equipment cooling systems, and the Refrigeration systems to serve the owner furnished Cray V Computer, the Amdahl Equipment, and the IBM equipment. Gerald Roy Spencer, P.E. was responsible for the data processing computer equipment layout within the constraints of the existing space.


23. NASA-JSC - BUILDING 16 - SHUTTLE FLIGHT SIMULATOR FOR SAIL PROGRAM - 1988 - $450,000 - This project involved the installation of isolated electrical power generation and distribution equipment, 400 HZ power generation and distribution system, raised computer floor, air conditioning and other modifications as required to convert a part of a high bay facility to a computer room with Shuttle Mock-ups used for Flight Training and Flight Mission project training.


24. NASA-JSC - BUILDING 16 - ROBOTIC ARM DEVELOPMENT AREA - 1989 - $350,000 - This project involved the installation of electrical power generation and distribution equipment, raised computer floor, air conditioning and other modifications as required to convert a part of the mezzanine of a high bay facility to a computer room to house robotic equipment that will be used to train personnel.


25. NASA-JSC - BUILDING 16 - SHUTTLE ELECTRONIC SIMULATOR GROUNDING PROBLEM SOLVING - 1989 - $550,000 - Gerald Roy Spencer, P.E. provided trouble shooting field work to locate the cause of and eliminate ground loops and power transients that were disrupting the computer operations. We were successful in improving the reliability of the electrical service to the shuttle electronic.


26. NASA-JSC - BUILDING 30 - 1987 - $123,000 - MISSION FLIGHT CONTROL CENTER - MODIFY POWER DISTRIBUTION SYSTEMS FOR INCREASED RELIABILITY - We modified the existing power feeders and added panels in the mission control center for increased reliability of the electrical service to the space.


27. NASA-JSC - BUILDING 30 - 1989 - $1,310,000 - MISSION FLIGHT CONTROL CENTER - REPLACE "B POWER SWITCHGEAR" - This project required the replacement of the electrical service to the Space Flight Mission Control Center in order to accommodate the addition of one additional 1350 KVA engine generator that operates in parallel with three existing 1350 KVA engine generators and two 3000 KVA pad mounted transformers. Closed transition switching from commercial power to site generated power was required. We performed short circuit fault calculations for each of the possible operating conditions. We performed breaker/fuse coordination studies to assure that branch faults would not trip circuit breakers.


28. NASA-JSC - 1987 - STUDY OF SITE ELECTRICAL SERVICE RELIABILITY TO ELECTRONIC DATA PROCESSING EQUIPMENT. RELIABILITY AND REDUNDANCY REQUIREMENTS: The reliability requirements for each building or load served needs to be determined and defined. Last year Spencer Engineers, Inc. performed a study DEFINING THE RELIABILITY OF THE EXISTING ELECTRICAL SERVICE TO CRITICAL DATA PROCESSING SYSTEMS AT NASA-JSC according to U. S. Army RELIABILITY REPORT REQUIREMENTS FOR COMMUNICATIONS NETWORKS. This involved a review of operational and maintenance logbooks to develop a data base of power failures MTBF and disturbances MTBD (Mean Time Between Failures or Disturbances) to data processing equipment caused by the power supply. Some disturbances were unexplained and we were not able to determine the origin/cause of the disturbance. The data base was analyzed to determine mean time between failures for the power serving each critical system. The service systems can be modified to increase.


29. NASA-JSC - BUILDING 12 - 1988 - $210,000 - MODIFY POWER SUPPLY TO DATA PROCESSING EQUIPMENT - Replaced existing building service switchgear.


30. NASA-JSC - BUILDING 35 - 1989 - $185,000 - MODIFY POWER SUPPLY TO DATA PROCESSING EQUIPMENT - Replaced existing building service switchgear.


31. NASA-JSC - BUILDING 17 - 1989 - $160,000 - MODIFY POWER SUPPLY TO DATA PROCESSING EQUIPMENT - Replaced existing building service switchgear.


32. NASA-JSC - BUILDING 4 - 1989 - $166,000 - MODIFY POWER SUPPLY TO DATA PROCESSING EQUIPMENT - Replaced existing building service switchgear.


33. GREENSPOINT DIAL BUILDING - HOUSTON, TEXAS - 1984 - $1,000,000 - This project is a new telephone equipment building on Greens Road by Houston Intercontinental Airport. This building has 20,000 SF of computer equipment. Gerald Roy Spencer, P.E. designed an UNINTERRUPTABLE POWER SYSTEMand STANDBY AIR CONDITIONING SYSTEM to serve this facility.


34. THE METHODIST HOSPITAL 3RD FLOOR CA SCAN UNIT - 1984 - This project involved installing new X-Ray equipment and computer imaging equipment.


35. HARRIS COUNTY JUVENILE DETENTION FACILITY - HOUSTON, TX - 1984 - $8,000,000 - This project is a story addition to the existing facility that more than doubled the capacity of the facility. This Project includes sophisticated security, Fire Alarm, five Fire Suppression, closed circuit TV, and monitoring systems. This project also included the renovation of the existing facility. Gerald Roy Spencer, P.E. designed an emergency power system to serve this facility. We were MEP.


36. BRAZORIA COUNTY DETENTION FACILITY - ANGLETON, TEXAS - 1984 - $5,000,000 - This project is a single story jail facility located outside the city of Angleton. This Project includes sophisticated security, Fire Alarm, Fire Suppression, closed circuit TV, and monitoring systems. Gerald Roy Spencer, P.E. designed an emergency power system to serve this facility. We were consultants to Brooks.


37. CAPITAL FAIRFAX THREE 225 KW EMERGENCY GENERATORS - 1980 - Gerald Roy Spencer, P.E. added three diesel driven 225 KW emergency generators as part of the UN-INTERRUPTIBLE POWER SYSTEM to the roof of the existing eleven story building. Gerald Roy Spencer, P.E. replaced the main switchboard. Gerald Roy Spencer, P.E. routed bus duct down to the basement.


38. BROOKHOLLOW CREDIT CARD CENTER POWER ANALYSIS - HOUSTON, TX - 1980 - Gerald Roy Spencer, P.E. provided trouble shooting field work to determine the source of transients that were disrupting the computer operations. 


39. COMPUTER POWER ANALYSIS AT THE FOLLOWING LOCATIONS: - 1979 - Gerald Roy Spencer, P.E. analyzed the cleanliness of the incoming power by installing Dranitz meters on the computer equipment and designed systems to prevent or minimize down time due to transients from the incoming power.1200 CLAY, ROOM 206. 151 NORTH POINT, ROOM 200.1114 TEXAS AVENUE, ROOM 1501. 1114 TEXAS AVENUE, ROOM 1401.3303 WESLAYAN, ROOM 208. 2922 PLUMB CREEK, ROOM 200.220 MAIN, ROOM 101, BEAUMONT. 1301 RICHMOND, ROOM 222.


40. ASHLAND TOLL BUILDING ELECTRICAL POWER ALTERATIONS - 1978 - Gerald Roy Spencer, P.E. designed an UN-INTERRUPTIBLE EMERGENCY.


41. UNMANNED MICROWAVE RELAY STATION POWER SUPPLY-IGNEK, ALASKA - 1978 - Gerald Roy Spencer, P.E. was employed directly by EXXON.


42. BAY CITY DIAL BUILDING ADDITION - BAY CITY, TEXAS - 1977 - $200,000.


43. COMPUTER ROOM - TEXAS CITY REFINING CO. - TEXAS CITY, TEXAS.


44. 472 GREENWOOD DIAL BUILDING ADDITION - PASADENA, TEXAS - 1976 - $1,000,000 - Gerald Roy Spencer, P.E. designed an emergency power system to serve this facility. This building has 40,000 SF of computer equipment. Gerald Roy Spencer, P.E. designed an UNINTERRUPTABLE POWER SYSTEM and STANDBY AIR CONDITIONING SYSTEM to serve this facility.


45. ASHLAND TOLL BUILDING REMODELING - HOUSTON, TEXAS - 1976 - $1,000,000 - Gerald Roy Spencer, P.E. designed an UNINTERRUPTABLE POWER SYSTEM and STANDBY AIR CONDITIONING SYSTEM to serve this facility.


46. SEVEN REMODELING PROJECTS TO VARIOUS SOUTHWESTERN BELL TELEPHONE COMPANY BUILDINGS TO RECEIVE COMPUTER EQUIPMENT IN HOUSTON, TEXAS - 1975-77 - $700,000 - Each building has about 5,000 SF.


47. 750 KVA TURBINE EMERGENCY GENERATOR 781 DIAL BUILDING - 1975 - Gerald Roy Spencer, P.E. designed an UN-INTERRUPTIBLE EMERGENCY.


48. SUNSET 781 DIAL BUILDING ADDITION - HOUSTON, TEXAS - 1974 - $1,200,000 - Gerald Roy Spencer, P.E. designed an UNINTERRUPTABLE POWER SYSTEM and STANDBY AIR CONDITIONING SYSTEM to serve this facility. 


49. GALVESTON COUNTY INFORMATION CENTER - GALVESTON, TEXAS - 1974 - $525,000 - This building has 4,000 SF of computer equipment.


50. REGIONAL AIRPORT FAA-TRACON FACILITY - DALLAS/FT. WORTH - 1973 - This project is the Control Tower and Air Route Traffic Control Center for the DFW Airport. This Project included sophisticated security, UNINTERRUPTABLE POWER SYSTEM, Fire Alarm, Fire Suppression, closed circuit TV, and monitoring systems. This Project included sophisticated Air Conditioning, with standby air conditioning for the computer systems. Gerald Roy Spencer, P.E. designed an emergency power system to serve this facility. We were MEP consultants to Welton.


51. WITTE ROAD INFORMATION CENTER - HOUSTON, TEXAS - 1971 - $500,000 - Gerald Roy Spencer, P.E. designed an emergency power system to serve this facility. This building has 4,000 SF of computer equipment.


power systems


Gerald Roy Spencer, P.E. has accomplished many Southwestern Bell Telephone Company projects, which are one in actuality a large built-up computer and Un-interruptible Power Systems. Gerald Roy Spencer, P.E. is the EOR for the construction of more than 40 raised floor data processing projects during the last 30 years, including seven projects totaling more than 75,000 sf of raised floor data processing equipment space in the last 10 years. The raised floor details generated by Gerald Roy Spencer, P.E.construction at NASA-JSC.

design process


Informal design/review meetings (undocumented) with our design team members and the end users are of great value, especially in the initial stages of the design process. We intentionally do not document these meetings in order to encourage free and open expression of ideas, preferences and opinions. This helps to allow group consideration of all possible design solutions. One person's bad idea might stimulate another persons good idea. The person with the bad idea might not mention the bad idea if he or she believes that it might be recorded, and come back to haunt him or her. We can deploy a design team consisting of design professionals in each of the required design disciplines required to the site.


The planning and programming for the conceptual design normally requires that the design team be on-site to document the requirements of each function and relations to other functions in detail. This will require interviewing the managers of each separate operation to determine current and future needs. This data resulting from end user interviews will also include end user equipment utility connection requirements in tabular form for each function and/or each space. This document will be considered a working document (usually a three ring binder) that will be currently be up-dated as the requirements for data processing, transmitters, antennae, and other data is up-dated until finalized.


The designers will familiarize themselves with operations and the facility requirements of the facility users. This document can be reproduced at each formal submittal and at additional milestones as required for use by designers and/or end users. This approved criteria will be used to formulate and design the building configuration. This is usually referred to as a Charette process.


The design team will submit formal and informal floor plans for discussion, comments, and/or approval by the used group while on site for the Charette process. Hopefully the floor plan can be approved by the used personnel before the Charette design team leaves the site. If the Charette plans are not approved prior to leaving the site, at least the planning problems will be documented and the Charette Plans will then be used as reference (during telephone conversations) tool for later design decisions. The Charette designers will work closely with the facility end users to create a facility design that enables the facility users to accomplish their mission.


Engineering system space requirements (HVAC, Plumbing, Fire Protection, Electrical, Structural, Security, etc.) will be determined at the Charette design and planning stage. This might entail familiarization with new and existing utility requirements to the point that we agree or have comments. This will also have on-site start of the engineering systems design in preliminary sketch fashions. Gerald Roy Spencer, P.E. will also conduct informal design meetings with the end users and facility operations and maintenance personnel during the Charette process.


space planning


Most manufacturers installation details work, but there are sometimes better ways to install the raised floors. Handrail details to comply with building codes are sometimes a structural problem. Gerald R. Spencer, P.E. has performed space planning for many different data processing facilities. These have also included the 20,000 SF Cray V Super Computer Systems, the Amdahl Super Computer Systems, and the IBM equipment that supports the systems for the EXXON Central Computer processing facility.


data processing facilities


Gerald Roy Spencer, P.E. is an expert at space planning and final design for data processing facilities. Spencer Engineers, Inc. (SEI) has vast experience in the design of computer facilities. Gerald Roy Spencer, P.E. has extensive experience with the installation of all types of computers including the CRAY, IBM, and Amdahl super computers. He has experience as the Engineer of Record (EOR) for the design and construction of 400 Hz power generation and distribution as required for super computers and Space Flight Simulation / Training for Spacecraft (similar to aircraft). He has experience with trouble shooting existing computer installations for sources of trouble causing transients. He has designed many Un-interruptible Power Systems.