SI Contract Specifications

ERDC TN-DOER-I6

March 2001

instrumentation subcontractors and consulting engineers also reviewed the specifications and

provided technical guidance. Detailed information about the SI contract specification guide can

be obtained from SI points of contact provided at the end of this document.

Because dredging contract requirements vary between Corps Districts, each District can tailor

the SI contract specifications to meet its specific dredging needs. In addition, these

specifications may differ from contract to contract within a District if different types of dredging

are required. However, one of the main purposes of the SI system is to standardize the

monitoring requirements so that a contractor's dredge may work for various Corps Districts with

a minimum amount of SI system modifications to meet disparate monitoring requirements. The

SI specifications are included in dredging contract bid packages distributed by the District.

In general, the SI contract specifications for hopper and pipeline dredges include details related

to the following topics:

DPIP requirements

Contractor-provided sensor and data requirements

Type, number, and locations

Quality control criteria

Minimum data performance requirements

Data reporting and format

Reference datum(s)

Contractor-provided computer equipment

Data-reporting interface requirements

Quality assurance test descriptions and requirements (predredging and during dredging)

Table of contractor-specific deliverables

DPIP submittal schedule

Data format examples and related definitions

One of the most important elements of the SI specifications is the format in which the SI data are

reported. The SI system has extended the National Marine Electronics Association (NMEA)

format commonly used by many instruments aboard dredges (NMEA 1998). The purpose of this

extended format is to provide a standardized data interface between the DSS and Ship Server for

all SI system measurements. The general data format for the SI system interface is given as

follows:

$Paaa,LABEL,x.x-----------------------------,*hh<CR><LF>

where

= Proprietary sentence identifier

= Three-letter manufacturer's mnemonic code

aaa